JP4512631B2 - Toner and method for producing the same, two-component developer, developing device, and image forming apparatus - Google Patents

Description

  The present invention relates to a toner, a method for producing the toner, a two-component developer, a developing device, and an image forming apparatus.

  Toner that visualizes a latent image is used in various image forming processes, and as an example, it is known to be used in an electrophotographic image forming process.

  In an image forming apparatus using an electrophotographic image forming process, generally, a charging process for uniformly charging a photosensitive layer on a surface of a photosensitive drum as a latent image carrier, and a surface of a charged photosensitive drum. An exposure process for projecting signal light of a document image to form an electrostatic latent image, a developing process for supplying an electrophotographic toner to the electrostatic latent image on the surface of the photosensitive drum to visualize it, and a toner on the surface of the photosensitive drum Use a cleaning blade to transfer the image onto a medium such as paper or an OHP sheet, a fixing process to fix the toner image on the medium by heating or pressing, and the toner remaining on the surface of the photosensitive drum after transferring the toner image. A desired image is formed on the media by performing a cleaning process that removes and cleans. Transfer of the toner image to the medium may be performed via an intermediate transfer medium. As the developer used in such an image forming apparatus, there are a one-component developer mainly composed of toner and a two-component developer using a mixture of toner and carrier. The toner used in these developers is produced by a polymerization method represented by, for example, a kneading and pulverizing method, a suspension polymerization method, and an emulsion polymerization aggregation method. In the kneading and pulverization method, the toner material, which is mainly composed of a binder resin and a colorant, and added with a release agent and a charge control agent as necessary, is melt-kneaded, cooled and solidified, and then pulverized. Toner is manufactured by classification.

  In recent years, many efforts have been made in various technical fields from the viewpoint of global environmental conservation. Currently, many raw materials for products are manufactured from petroleum, but efforts to reduce the carbon dioxide generated during the production and incineration of these raw materials and the required energy are from the perspective of preventing global warming. Very important.

  Therefore, the use of plant-derived resources called biomass has attracted a great deal of attention as a new initiative that helps prevent global warming. Carbon dioxide generated when biomass is burned is atmospheric carbon dioxide originally taken by plants by photosynthesis, so the overall balance of carbon dioxide in the atmosphere is zero and the total amount does not change. In this way, the property that does not affect the increase or decrease of carbon dioxide in the atmosphere is called carbon neutral, and it is possible to fix the amount of carbon dioxide in the atmosphere by using plant-derived resources that are carbon neutral. it can. Plastics produced from such biomass are called by names such as biomass polymer, biomass plastic, and non-petroleum polymer material, and monomers used as these raw materials are called biomass monomers.

  In the field of electrophotography, in consideration of global environmental conservation, efforts are being made to use biodegradable resins including biomass, which is excellent in environmental safety and effective in reducing carbon dioxide.

  For example, a polyester resin is generally produced by polycondensation of a dicarboxylic acid and a diol, but a biomass monomer such as succinic acid or itaconic acid is used as the dicarboxylic acid component, and 1,3-propane is used as the diol component. A technique has been proposed in which a polyester resin produced using a biomass monomer such as a diol is used as a binder resin for a color toner.

  In addition, a technique has been proposed in which polylactic acid resin, which is a biomass polymer produced using lactic acid obtained from plants such as corn as a raw material, is used as a binder resin for toner. Since polylactic acid resin can be molded in various ways, it has the potential to become a new general-purpose resin, and has already been sold industrially.

  For example, Patent Document 1 discloses a toner that includes a binder resin and a colorant, and is particularly suitable for a flash fixing method, and the binder resin includes a combination of an ester-type resin and a polylactic acid resin. Thus, an electrophotographic toner exhibiting an excellent toner fixing rate and a high safety to the human body and the environment is disclosed. Patent Document 2 discloses a toner containing a binder resin, a colorant, and a charge control agent, wherein the binder resin contains a biodegradable resin such as a polylactic acid resin, and the charge control agent has a repetitive structure. A toner for developing an electrostatic charge image that exhibits a stable charging behavior even when continuously printed by containing a polyamine having a good image without fluctuations in image density and is highly safe for the environment is disclosed. .

  In addition, energy conservation is being studied from various angles as another initiative that helps prevent global warming. In the field of electrophotography, by reducing the fixing temperature of toner transferred onto media such as paper and OHP sheets. There is a growing recognition that reducing fixing energy is effective. Further, further speeding up of copying machines and facsimile machines is also desired. From these trends, it is indispensable to lower the melting point of the toner.

  As a method for fixing a toner image transferred on a medium such as paper or an OHP sheet, a contact heating type fixing method in which a toner image is heated and melted by a heat roll or the like and is pressed and fixed is often used. The fixability of the toner in the system can be evaluated by the fixable temperature range from the lower limit fixing temperature to the hot offset start temperature. The lowering of the melting point of the toner described above means lowering the lower limit fixing temperature, whereby low temperature fixing can be achieved. As the binder resin for toner, a resin having a crosslinked structure or a resin containing a high molecular weight substance and a low molecular weight substance is used. In such a binder resin, a crosslinking component is used to improve hot offset resistance. If the content of the high molecular weight component is increased, the melt viscosity of the resin becomes too high, and the low-temperature fixability of the toner may be insufficient. On the other hand, if the content of the low molecular weight substance is increased in order to improve the low-temperature fixability, the melt viscosity of the resin is reduced, but the elasticity of the toner is lowered and the hot offset resistance may be lowered. Therefore, the design of the binder resin for toner is particularly important in order to achieve a low melting point of the toner and to maintain the offset resistance at high temperatures.

  In order to achieve low temperature fixing and reduce fixing energy, a technique as shown in Patent Document 3 has also been proposed. Patent Document 3 contains a toner composed of toner particles composed of at least a colorant and a binder resin mainly composed of a crystalline resin, and the toner has a melting point of 50 ° C. to 120 ° C. A full-color image forming method using a developer having an average crystal size of the crystalline resin in a fixed image of 3 μm is disclosed.

JP 2001-22123 A JP 2004-184444 A JP 2002-72567 A

  In the techniques disclosed in Patent Documents 1 and 2, it is difficult to uniformly disperse polylactic acid in the toner due to a difference in physical properties between the resin that is the main component of the binder resin for toner and polylactic acid. is there. When polylactic acid is dispersed non-uniformly in the toner, the dispersion of the particle size distribution due to the unevenness of the pulverization property of the toner, the influence on the fixability due to the unevenness of the melt viscosity, the charging property due to the unevenness of the resin composition In addition to unevenness in physical properties among toner particles, such as variations, there is a risk of variations in light transmittance and deterioration.

  The technology disclosed in Patent Document 3 improves the low-temperature fixability by lowering the minimum fixing temperature of the binder resin without lowering the glass transition point by utilizing the sharp melt property of the crystalline resin. However, sufficient low-temperature fixability and hot offset resistance are not obtained, and good storage stability is not obtained. In addition, when fixing on a medium such as paper or an OHP sheet, if the crystalline resin is melted and then recrystallized by cooling and solidifying, the dispersion state of the crystalline resin becomes non-uniform, and the light transmission property is increased. There is a risk of bias.

  The present invention has been made in view of the above-mentioned problems, and its object is to consider the preservation of the global environment, and is excellent in fixing property and storage stability, and also has good light transmission properties and toners thereof. A manufacturing method, a two-component developer, a developing device, and an image forming apparatus are provided.

The present invention is a toner comprising at least a binder resin and a colorant,
The binder resin is configured to include a resin as a main component and a crystalline resin containing biomass,
The crystalline resin is contained in an amount of 1 to 50 parts by weight with respect to 100 parts by weight of the binder resin, and the melting point of the crystalline resin is such that the loss elastic modulus G ″ of the toner at a frequency of 1 Hz is 10 ³ Pa. The toner is characterized in that the temperature is 5 to 10 ° C. higher than the above temperature.

The toner of the present invention is characterized in that the crystalline resin includes a unit represented by the following formula (1).
_{- [O-CH (CH 3} ) -CO] n - ... (1)
(In the formula, n represents a positive integer.)

  The toner of the present invention is characterized in that the main resin is a polyester resin.

In the toner of the present invention, the loss elastic modulus G ″ at 120 ° C. of the toner is 10 ⁵ Pa or less, the loss elastic modulus G ″ at 200 ° C. is 10 ¹ Pa or more, and the loss elastic modulus G ″ at 200 ° C. is stored. The loss tangent, which is a value divided by the elastic modulus G ′, is 10 or less.

The present invention is also a method for producing the toner,
A pre-mixing step of preparing a mixture by mixing at least a resin as a main component and a binder resin comprising a crystalline resin containing biomass and a colorant;
A melt-kneading step of melt-kneading a mixture containing a crystalline resin in an amount of 1 part by weight or more and 50 parts by weight or less with respect to 100 parts by weight of a binder resin;
A pulverization step of pulverizing the melt-kneaded product to produce a pulverized product;
And a classification step of removing excessively pulverized material and coarse powder from the pulverized material.

  The toner production method of the present invention is characterized in that in the melt-kneading step, the mixture is melt-kneaded using a two-roll type continuous kneader.

According to another aspect of the present invention, there is provided a two-component developer comprising the toner and a carrier.
In addition, the present invention is a developing device that performs development using the toner or the two-component developer.

The present invention also provides an image forming apparatus comprising the developing device.
In addition, the image forming apparatus of the present invention includes a fixing unit that heats and fixes a toner image formed on a recording medium.

  According to the present invention, in a toner that includes at least a binder resin and a colorant, the binder resin includes a resin that is a main component and a crystalline resin that includes biomass.

  As described above, the binder resin includes the resin as the main component, so that the molecular weight distribution can be controlled to be an optimum value in order to obtain excellent low-temperature fixability. Further, by including a crystalline resin containing biomass, it is possible to obtain a carbon neutral toner in consideration of global environment conservation. Furthermore, excellent hot offset resistance can be obtained by the filler effect resulting from the dispersion of the crystalline resin in the toner. Therefore, it is possible to maintain good fixing properties and storage stability.

  Further, when the crystalline resin is contained in an amount of 1 to 50 parts by weight with respect to 100 parts by weight of the binder resin, the dispersibility of the crystalline resin in the toner can be kept good.

Further, the melting point of the crystalline resin is 5 ° C. to 10 ° C. higher than the temperature at which the loss elastic modulus G ″ of the toner at a frequency of 1 Hz is 10 ³ Pa. Since it can be fixed, the dispersion state of the crystalline resin can be maintained, and good fixing property can be obtained, and the dispersion state is prevented from becoming non-uniform due to recrystallization after fixing. Therefore, deterioration of light transmittance can be suppressed.

  Therefore, the toner of the present invention is a toner that is considered for global environmental conservation, has excellent fixing properties and storage stability, and has good light transmission properties.

Moreover, according to this invention, it is preferable that crystalline resin is comprised including the unit shown by following formula (1).
_{- [O-CH (CH 3} ) -CO] n - ... (1)
(In the formula, n represents a positive integer.)

  As a result, it is possible to obtain a toner that is further considered for global environmental conservation, is excellent in environmental safety, and is effective in reducing carbon dioxide.

  According to the invention, the resin as the main component is preferably a polyester resin. As a result, it is possible to obtain an optimum toner for a color toner having excellent sharp melt properties and durability. In addition, a color toner having excellent low-temperature fixability and excellent color developability can be obtained.

According to the invention, the loss elastic modulus G ″ at 120 ° C. of the toner is 10 ⁵ Pa or less, the loss elastic modulus G ″ at 200 ° C. is 10 ¹ Pa or more, and the loss elastic modulus G ″ at 200 ° C. is stored. The loss tangent, which is a value divided by the elastic modulus G ′, is preferably 10 or less, so that a sufficient fixable temperature range from the minimum fixing temperature to the hot offset start temperature, which is an index of toner fixability, is obtained. be able to.

  According to the invention, the toner manufacturing method mixes at least a resin that is a main component and a binder resin that includes a crystalline resin containing biomass and a colorant to produce a mixture. A pre-mixing step, a melt-kneading step for preparing a melt-kneaded product by melt-kneading a mixture containing crystalline resin in an amount of 1 to 50 parts by weight with respect to 100 parts by weight of the binder resin, A pulverization step of pulverizing to produce a pulverized product, and a classification step of removing excessively pulverized product and coarse powder from the pulverized product.

  As a result, the toner of the present invention, which is considered for the preservation of the global environment, has excellent fixability and storage stability, and has good light transmittance, can be reduced using the simplest equipment among various toner production methods. Can be manufactured at cost.

  Further, according to the present invention, in the melt-kneading step, the dispersibility of the toner material is further improved by using a two-roll type continuous kneader to melt-knead the mixture as compared with the case of using another conventional kneader. To do. Therefore, since the uniformity of the crystalline resin in the toner is improved and finely dispersed, it is possible to prevent the light transmittance from being deteriorated. Furthermore, the hot offset resistance due to the filler effect of the crystalline resin can be improved.

  Further, according to the present invention, the two-component developer of the present invention includes the toner and the carrier, so that the environmental protection is considered, the fixing property and the storage stability are excellent, and the light transmittance is excellent. Such a two-component developer can be obtained.

  According to the invention, the developing device of the invention can maintain the storage stability while ensuring the fixing property of the toner by performing the development using the toner or the two-component developer. Stable performance can be maintained against stress such as stirring in the developing tank.

  In addition, according to the present invention, the image forming apparatus of the present invention includes the developing device of the present invention, thereby forming a stable high-quality image excellent in fixability and color developability without causing trouble over a long period of time. can do.

  Further, according to the present invention, it is preferable that the image forming apparatus of the present invention includes a fixing unit that melts and fixes the toner image formed on the recording medium. As described above, by using the toner of the present invention to form a fixed image by the image forming apparatus provided with the above-described fixing unit, it is possible to effectively draw out toner physical properties that achieve both low-temperature fixability and storage stability. A quality image can be obtained.

The toner of the present invention is a toner that includes at least a binder resin and a colorant, and the binder resin includes a resin that is a main component and a crystalline resin that includes biomass. The crystalline resin is contained in an amount of 1 to 50 parts by weight with respect to 100 parts by weight of the binder resin, and the melting point of the crystalline resin is such that the loss elastic modulus G ″ of the toner at a frequency of 1 Hz is 10 ³ Pa. The temperature is 5 ° C to 10 ° C higher than the temperature.

  As described above, the binder resin includes the resin as the main component, so that the molecular weight distribution can be controlled to be an optimum value in order to obtain excellent low-temperature fixability. Further, by including a crystalline resin containing biomass, it is possible to obtain a carbon neutral toner in consideration of global environment conservation. Furthermore, excellent hot offset resistance can be obtained by the filler effect resulting from the dispersion of the crystalline resin in the toner. Therefore, it is possible to maintain good fixing properties and storage stability.

  Further, when the crystalline resin is contained in an amount of 1 to 50 parts by weight with respect to 100 parts by weight of the binder resin, the dispersibility of the crystalline resin in the toner can be kept good.

Further, the melting point of the crystalline resin is 5 ° C. to 10 ° C. higher than the temperature at which the loss elastic modulus G ″ of the toner at a frequency of 1 Hz is 10 ³ Pa. Since it can be fixed, the dispersion state of the crystalline resin can be maintained, and good fixing property can be obtained, and the dispersion state is prevented from becoming non-uniform due to recrystallization after fixing. Therefore, deterioration of light transmittance can be suppressed.

The temperature at which the loss elastic modulus G ″ of the toner at a frequency of 1 Hz is 10 ³ Pa is a temperature corresponding to the fixing temperature of the toner. The fixing temperature of the toner is a set temperature of the fixing device in the heat roll fixing method. It is a temperature near the center of the fixable temperature range.

  Therefore, the toner of the present invention is a toner that is considered for global environmental conservation, has excellent fixing properties and storage stability, and has good light transmission properties.

  The method for producing the toner of the present invention will be described below. The toner manufacturing method of the present invention is, for example, the toner manufacturing method shown in the flowchart of FIG. FIG. 1 is a flowchart showing an example of a procedure in the toner manufacturing method of the present invention.

  As shown in FIG. 1, the toner manufacturing method of the present invention mixes at least a binder resin composed of a resin that is a main component and a crystalline resin containing biomass and a colorant. A pre-mixing step (step S1) for preparation, and a melt-kneading step for preparing a melt-kneaded product by melt-kneading a mixture containing crystalline resin in an amount of 1 part by weight to 50 parts by weight with respect to 100 parts by weight of the binder resin (Step S2), a pulverization step (Step S3) for pulverizing the melt-kneaded product to produce a pulverized product, and a classification step (Step S4) for removing excessively pulverized product and coarse powder from the pulverized product.

  Below, each manufacturing process of step S1-step S4 is demonstrated in detail. Transition from step S0 to step S1 starts the production of the toner of the present invention.

[Pre-mixing process]
In the pre-mixing step of step S1, at least the binder resin and the colorant are dry-mixed by a mixer to prepare a mixture. The mixture may contain other toner additive components in addition to the binder resin and the colorant. Examples of other toner additive components include a release agent and a charge control agent.

  A known mixer can be used for dry mixing. For example, a Henschel mixer (trade name: FM mixer, manufactured by Mitsui Mining Co., Ltd.), a super mixer (trade name, manufactured by Kawata Co., Ltd.), a mechano mill (product) Name, Okada Seiko Co., Ltd. and other Henschel type mixing devices, Ongmill (trade name, manufactured by Hosokawa Micron Co., Ltd.), hybridization system (trade name, manufactured by Nara Machinery Co., Ltd.), Cosmo System (trade name, Kawasaki Heavy Industries, Ltd.) Etc.).

Below, each raw material of the toner contained in a mixture is demonstrated.
(A) Binder Resin The binder resin included in the toner of the present invention includes a resin as a main component and a crystalline resin containing biomass.

  By comprising the binder resin containing the resin as the main component, the molecular weight distribution can be controlled to an optimum value in order to obtain excellent low-temperature fixability. Further, by including a crystalline resin containing biomass, it is possible to obtain a carbon neutral toner in consideration of global environment conservation. Furthermore, excellent hot offset resistance can be obtained by the filler effect resulting from the dispersion of the crystalline resin in the toner. Therefore, it is possible to maintain good fixing properties and storage stability.

  As the resin as the main component, a general thermoplastic resin can be used, and examples thereof include polyester resin, acrylic resin, polyurethane resin, and epoxy resin. These resins may be used alone or in combination of two or more. Further, in the same type of resin, two or more types of resins having different one or more physical properties such as molecular weight and monomer composition may be used in combination.

  The polyester resin is not particularly limited, and known resins can be used. Examples thereof include polycondensation products of polybasic acids and polyhydric alcohols. Polybasic acids are polybasic acids and derivatives of polybasic acids such as acid anhydrides or esterified products of polybasic acids. Polyhydric alcohols are compounds containing two or more hydroxyl groups, and include both alcohols and phenols.

  As polybasic acids, those commonly used as monomers of polyester resins can be used, for example, aromatic carboxylic acids such as terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic acid and naphthalenedicarboxylic acid, Mention may be made of aliphatic carboxylic acids such as maleic anhydride, fumaric acid, succinic acid and adipic acid. Polybasic acids may be used alone or in combination of two or more.

  Polyhydric alcohols that are commonly used as monomers of polyester resins can be used, for example, aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol and glycerin, cyclohexanediol, Examples include alicyclic polyhydric alcohols such as cyclohexanedimethanol and hydrogenated bisphenol A, and aromatic diols such as bisphenol A ethylene oxide adduct and bisphenol A propylene oxide adduct. “Bisphenol A” is 2,2-bis (p-hydroxyphenyl) propane. Examples of the ethylene oxide adduct of bisphenol A include polyoxyethylene-2,2-bis (4-hydroxyphenyl) propane. Examples of the propylene oxide adduct of bisphenol A include polyoxypropylene-2,2-bis (4-hydroxyphenyl) propane. Polyhydric alcohols may be used alone or in combination of two or more.

  The polyester resin can be synthesized by a condensation polymerization reaction. For example, it can be synthesized by polycondensation reaction, specifically dehydration condensation reaction of polybasic acids and polyhydric alcohols in the presence of a catalyst in an organic solvent or without solvent. At this time, a demethanol polycondensation reaction may be carried out using a methyl esterified product of a polybasic acid as part of the polybasic acid. The polycondensation reaction between the polybasic acid and the polyhydric alcohol may be terminated when the acid value and softening temperature of the polyester resin to be produced reach the values in the polyester resin to be synthesized. In this polycondensation reaction, by appropriately changing the reaction conditions such as the blending ratio of polybasic acids and polyhydric alcohols and the reaction rate, for example, the content of carboxyl groups bonded to the terminal of the resulting polyester resin, and thus By adjusting the acid value of the obtained polyester resin, other physical property values such as the softening temperature can be adjusted.

  The acrylic resin is not particularly limited, and known ones can be used. Examples thereof include a homopolymer of an acrylic monomer and a copolymer of an acrylic monomer and a vinyl monomer. Among these, an acrylic resin having an acidic group is preferable. As the acrylic monomer, those commonly used as acrylic resin monomers can be used. For example, acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, acrylic Acrylate monomers such as n-amyl acid, isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, decyl acrylate and dodecyl acrylate, and methyl methacrylate, methacrylic acid Propyl acid, n-butyl methacrylate, isobutyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, decyl methacrylate and dodecyl methacrylate Like methacrylic acid ester monomers such as. These acrylic monomers may have a substituent. Examples of the acrylic monomer having a substituent include an acrylic ester monomer or a methacrylate ester monomer having a hydroxyl group such as hydroxyethyl acrylate and hydroxypropyl methacrylate. One acrylic monomer may be used alone, or two or more acrylic monomers may be used in combination. Known vinyl monomers can be used, for example, aromatic vinyl monomers such as styrene and α-methylstyrene, aliphatic vinyl monomers such as vinyl bromide, vinyl chloride and vinyl acetate, acrylonitrile and methacrylate. Examples include acrylonitrile monomers such as nitrile. A vinyl monomer may be used individually by 1 type, and may be used in combination of 2 or more type.

  The acrylic resin is, for example, one or more acrylic monomers, one or more acrylic monomers, and one or more vinyl monomers in the presence of a radical polymerization initiator. Further, it can be produced by polymerizing by a solution polymerization method, a suspension polymerization method or an emulsion polymerization aggregation method. An acrylic resin having an acidic group is, for example, an acrylic monomer or an acrylic monomer containing an acidic group or a hydrophilic group and a vinyl type having an acidic group or a hydrophilic group when an acrylic monomer or an acrylic monomer and a vinyl monomer are polymerized. It can be produced by using either one or both of the monomers.

  It does not restrict | limit especially as a polyurethane resin, A well-known thing can be used, For example, the addition polymerization product of a polyol and polyisocyanate is mentioned. Among these, a polyurethane resin having an acidic group or a basic group is preferable. The polyurethane resin having an acidic group or a basic group can be synthesized, for example, by subjecting a polyol having an acidic group or a basic group to a polyisocyanate by an addition polymerization reaction. Examples of the polyol having an acidic group or basic group include diols such as dimethylolpropionic acid and N-methyldiethanolamine, polyether polyols such as polyethylene glycol, polyester polyols, acrylic polyols, and polybutadiene polyols. Examples include polyols. A polyol can be used individually by 1 type or can use 2 or more types together. Examples of the polyisocyanate include tolylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate. A polyisocyanate may be used individually by 1 type, and may be used in combination of 2 or more type.

  The epoxy resin is not particularly limited, and a known one can be used. For example, bisphenol A type epoxy resin synthesized from bisphenol A and epichlorohydrin, synthesized from phenol novolak and epichlorohydrin which are reaction products of phenol and formaldehyde. Phenol novolac type epoxy resin, and cresol novolak type epoxy resin synthesized from cresol novolak and epichlorohydrin which are reaction products of cresol and formaldehyde. Among these, an epoxy resin having an acidic group or a basic group is preferable. The epoxy resin having an acidic group or a basic group is based on, for example, the above-mentioned epoxy resin, and a polycarboxylic acid such as adipic acid or trimellitic anhydride or an amine such as dibutylamine or ethylenediamine is added to the base epoxy resin. It can be produced by addition or addition polymerization.

In the binder resin, the resin as the main component is preferably a polyester resin among the aforementioned resins. By using a polyester resin as the resin that is the main component of the binder resin, it is possible to obtain an optimum toner for a color toner having both excellent sharp melt properties and durability. In addition, since the polyester resin has a lower softening temperature (T _1/2 ) than other resins such as an acrylic resin, a toner having excellent low-temperature fixability that can be fixed at a lower temperature can be obtained by using the polyester resin. Obtainable. Furthermore, since the polyester resin is excellent in transparency, by using the polyester resin, it is possible to obtain a color toner having excellent color developability and excellent secondary color developability produced by superimposing with other color toners. Can do.

  The glass transition temperature (Tg) of the resin as the main component is not particularly limited and can be appropriately selected from a wide range. However, considering the fixing property and storage stability of the obtained toner, it is 30 ° C. or higher and 80 ° C. or lower. Is preferred. When the temperature is less than 30 ° C., the storage stability becomes insufficient, so that the toner is likely to thermally aggregate inside the image forming apparatus, which may cause development failure. Also, the temperature at which the hot offset phenomenon starts to occur (hereinafter referred to as “hot offset start temperature”) is lowered. “Hot offset phenomenon” means that when toner is fixed on a recording medium by heating and pressurizing with a fixing member such as a heating roller, the cohesive force of toner particles adheres between the toner and the fixing member due to overheating of the toner. This is a phenomenon in which the toner layer is divided below the force and a part of the toner adheres to the fixing member and is removed. On the other hand, when the temperature exceeds 80 ° C., the fixing property is deteriorated, so that fixing failure may occur.

The softening temperature (T _1/2 ) of the resin as the main component is not particularly limited and can be appropriately selected from a wide range, but is preferably 150 ° C. or lower, and more preferably 60 ° C. or higher and 120 ° C. or lower. . When the temperature is lower than 60 ° C., the storage stability of the toner is lowered, and the toner is likely to be thermally aggregated inside the image forming apparatus, so that the toner cannot be stably supplied to the image carrier and development failure occurs. There is a risk. In addition, a failure of the image forming apparatus may be induced. If the temperature exceeds 120 ° C., the binder resin is difficult to melt in the melt-kneading step, so that it becomes difficult to knead each raw material of the toner, and the dispersibility of the colorant, release agent, charge control agent, etc. in the melt-kneaded product May decrease. Further, when the toner is fixed on the recording medium, the toner is difficult to melt or soften, so that the fixability of the toner to the medium (recording medium) is lowered, and there is a possibility that a fixing defect occurs.

The molecular weight of the resin as the main component is not particularly limited and can be appropriately selected from a wide range, but is preferably 5000 to 500,000 in terms of weight average molecular weight (Mw). If it is less than 5000, the mechanical strength of the binder resin is lowered, and the resulting toner particles are easily pulverized by stirring inside the developing device, and the shape of the toner particles changes, for example, the charging performance varies. There is a fear. On the other hand, if it exceeds 500,000, it becomes difficult to melt, so that kneading in the melt-kneading step becomes difficult, and the dispersibility of the colorant, release agent, charge control agent and the like in the melt-kneaded product may be lowered. In addition, the fixing property of the toner is lowered, and there is a possibility that fixing failure occurs. Here, the weight average molecular weight is determined by gel permeation chromatography (Gel
Permeation chromatography (abbreviation: GPC) is a value in terms of polystyrene measured by GPC).

  The crystalline resin is not particularly limited as long as it contains biomass. Examples of biomass include lactic acid-based polymers, specifically, polylactic acid resins, copolymers of lactic acid and other hydroxycarboxylic acids, and the like. Examples of other hydroxycarboxylic acid used as a comonomer include glycolic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxypentanoic acid, hydroxycaproic acid, hydroxyheptanoic acid and the like. The aforementioned lactic acid-based polymer is a carbon neutral biomass polymer.

  These lactic acid-based polymers can be obtained by dehydrating polycondensation using L-lactic acid, D-lactic acid and other hydroxycarboxylic acids having a necessary structure as a raw material. In particular, it is preferably obtained by ring-opening polymerization by selecting a desired structure from lactide, which is a cyclic dimer of lactic acid, glycolide, which is a cyclic dimer of glycolic acid, and caprolactone.

Thus, the crystalline resin is preferably a lactic acid-based polymer as described above, that is, including a unit represented by the following formula (1), and more preferably a polylactic acid resin. .
_{- [O-CH (CH 3} ) -CO] n - ... (1)
(In the formula, n represents a positive integer.)

  As a result, it is possible to obtain a toner that is further considered for global environmental conservation, is excellent in environmental safety, and is effective in reducing carbon dioxide.

  Lactide, which is a raw material for polylactic acid resin, includes L-lactide, which is a cyclic dimer of L-lactic acid, D-lactide, which is a cyclic dimer of D-lactic acid, and D-lactic acid and L-lactic acid. There are quantified meso-lactide and DL-lactide, which is a racemic mixture of D-lactide and L-lactide. Any lactide can be used in the present invention.

  It does not specifically limit as a manufacturing method of polylactic acid resin, A conventionally well-known method can be used. For example, lactide, which is a cyclic dimer of lactic acid, is heated and melted and uniformly mixed, and then heat-opening polymerization is performed using a known polymerization catalyst, or dehydration polycondensation is performed directly from a lactic acid monomer by heating and decompression. The method etc. are mentioned.

  The polymerization catalyst used in the above-described polymerization reaction is not particularly limited, but a known lactic acid polymerization catalyst can be used. For example, tin compounds such as tin octylate, tin lactate, tin tartrate, tin dicaprylate, tin dilaurate, tin dipalmitate, tin distearate, tin dioleate, α-naphthoate, β-naphthoate; Tin powder, tin oxide; zinc dust, zinc halide, zinc oxide, organic zinc compounds; titanium compounds such as tetrapropyl titanate; zirconium compounds such as zirconium isopropoxide; antimony compounds such as antimony trioxide; oxidation Examples thereof include bismuth compounds such as bismuth (III); aluminum compounds such as aluminum oxide and aluminum isopropoxide. The amount of these polymerization catalysts used is, for example, about 0.001 to 5% by weight based on lactide when ring-opening polymerization is performed. The polymerization reaction varies depending on the catalyst type in the presence of the above-described polymerization catalyst, but can be usually performed at a temperature of 100 ° C to 220 ° C.

  In addition, the molar ratio of the D-lactic acid unit to the L-lactic acid unit in the polylactic acid resin is not particularly limited, and may be appropriately selected so that the melting point and the like are in a desired numerical range.

  The crystalline resin is contained in an amount of 1 to 50 parts by weight, particularly preferably 10 to 40 parts by weight, with respect to 100 parts by weight of the binder resin. When the content of the binder resin is 1 part by weight or more and 50 parts by weight or less, the dispersibility of the crystalline resin in the toner can be kept good. When the content exceeds 50 parts by weight, it is difficult to obtain a molecular weight distribution optimal for low-temperature fixing, and the fixability may be deteriorated. Further, it may be difficult to melt and knead the toner raw materials. If the content is less than 1 part by weight, the effects obtained by containing the crystalline resin may not be sufficiently obtained.

The melting point (Tm) of the crystalline resin is a temperature that is 5 ° C. to 10 ° C. higher than the temperature at which the loss elastic modulus G ″ of the toner at a frequency of 1 Hz is 10 ³ Pa. As a result, the crystalline resin in the toner is Since the toner can be fixed at a temperature that does not melt, it is possible to maintain the dispersion state of the crystalline resin and obtain a good fixing property, and by recrystallization of the crystalline resin after fixing. Since it is possible to prevent the dispersion state from becoming uneven, it is possible to suppress the deterioration of light transmission, so that the toner of the present invention has no bias in light transmission uniformity and is suitable as a color toner. The above-mentioned recrystallization refers to a phenomenon in which, when fixing on a medium such as paper or an OHP sheet, the crystallized resin is melted and then cooled and solidified to recrystallize. .

When the melting point (Tm) of the crystalline resin exceeds a temperature 10 ° C. higher than the temperature at which the loss elastic modulus G ″ of the toner at a frequency of 1 Hz becomes 10 ³ Pa, the fixability and the storage stability may be deteriorated. Further, when the melting point (Tm) is lower than the temperature 5 ° C. higher than the temperature at which the loss elastic modulus G ″ of the toner at a frequency of 1 Hz is 10 ³ Pa, the light transmittance may be deteriorated.

In this specification, the melting point (Tm) is the differential scanning calorimetry (Differential).
It is the temperature of the endothermic peak corresponding to melting of the DSC curve obtained by Scanning Calorimetry (abbreviation DSC).

  The molecular weight of the crystalline resin is not particularly limited and can be appropriately selected from a wide range. The molecular weight of each of the resin as the main component and the crystalline resin is not particularly limited, and is appropriately selected so that the molecular weight distribution of the toner falls within the optimum numerical range in order to obtain excellent hot offset resistance and low-temperature fixability. It only has to be done.

  The glass transition temperature (Tg) of the crystalline resin is not particularly limited and may be appropriately selected depending on the combination with the resin as the main component.

(B) Colorant Examples of the colorant include dyes and pigments. Among these, it is preferable to use a pigment. Since pigments are superior in light resistance and color developability compared to dyes, toners excellent in light resistance and color developability can be obtained by using pigments. Specific examples of the colorant include, for example, a yellow toner colorant, a magenta toner colorant, a cyan toner colorant, and a black toner colorant, as described below. Hereinafter, the color index is abbreviated as “CI”.

  Examples of the colorant for yellow toner include C.I. I. Pigment yellow 1, C.I. I. Pigment yellow 5, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 15 and C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 180, C.I. I. Organic pigments such as CI Pigment Yellow 185, inorganic pigments such as yellow iron oxide and ocher, C.I. I. Nitro dyes such as Acid Yellow 1, C.I. I. Solvent Yellow 2, C.I. I. Solvent Yellow 6, C.I. I. Solvent Yellow 14, C.I. I. Solvent Yellow 15, C.I. I. Solvent Yellow 19, and C.I. I. Examples thereof include oil-soluble dyes such as Solvent Yellow 21.

  Examples of the colorant for magenta toner include C.I. I. Pigment red 49, C.I. I. Pigment red 57, C.I. I. Pigment red 81, C.I. I. Pigment red 122, C.I. I. Solvent Red 19, C.I. I. Solvent Red 49, C.I. I. Solvent Red 52, C.I. I. Basic Red 10 and C.I. I. Disperse Red 15 etc. are mentioned.

  Examples of the colorant for cyan toner include C.I. I. Pigment blue 15, C.I. I. Pigment blue 16, C.I. I. Solvent Blue 55, C.I. I. Solvent Blue 70, C.I. I. Direct Blue 25, and C.I. I. Direct Blue 86 and KET. BLUE111 etc. are mentioned.

  Examples of the colorant for black toner include carbon black such as channel black, roller black, disk black, gas furnace black, oil furnace black, thermal black, and acetylene black. From these various types of carbon black, an appropriate carbon black may be appropriately selected according to the design characteristics of the toner to be obtained.

  In addition to these pigments, red pigments and green pigments can be used. A coloring agent can be used individually by 1 type, or can use 2 or more types together. Two or more of the same color can be used, and one or more of the different colors can also be used.

  The colorant is preferably used as a masterbatch. A master batch of a colorant can be produced, for example, by kneading a synthetic resin melt and a colorant. As the synthetic resin, a resin having the same compatibility as the resin that is the main component in the toner binder resin or a resin that is the main component in the toner binder resin is used. The use ratio of the synthetic resin and the colorant is not particularly limited, but is preferably 30 parts by weight or more and 100 parts by weight or less with respect to 100 parts by weight of the synthetic resin. The master batch is used after being granulated to a particle size of about 2 mm to 3 mm, for example.

  The content of the colorant in the toner of the present invention is not particularly limited, but is preferably 4 parts by weight or more and 20 parts by weight or less with respect to 100 parts by weight of the binder resin. When using a masterbatch, it is preferable to adjust the usage amount of the masterbatch so that the content of the colorant in the toner of the present invention falls within the above range. When the content of the colorant is within the above range, it is possible to obtain a toner that suppresses the filler effect due to the addition of the colorant and has high coloring power. Further, it is possible to form a good image having a sufficient image density, high color developability and excellent image quality. If the content of the colorant exceeds 20 parts by weight, the elasticity of the colorant may increase due to the filler effect of the colorant, and the toner fixability may decrease.

(C) Release agent The release agent is added to impart releasability to the toner when the toner is fixed on the recording medium. Therefore, the hot offset start temperature can be increased and the hot offset resistance can be improved as compared with the case where no release agent is used. Furthermore, low temperature fixability can be improved by melting the release agent by heating at the time of fixing the toner to lower the fixing start temperature.

  As the release agent, those commonly used in this field can be used, and examples thereof include wax. As the wax, paraffin wax. Examples include natural waxes such as carnauba wax and rice wax, synthetic waxes such as polypropylene wax, polyethylene wax and Fischer-Tropsch wax, petroleum waxes such as coal waxes such as montan wax, alcohol waxes, and ester waxes. . A mold release agent may be used individually by 1 type, and may be used in combination of 2 or more type.

  The compounding amount of the release agent is not particularly limited, and is appropriately selected from a wide range according to various conditions such as the type and content of other components such as a binder resin and a colorant and the characteristics required for the toner to be produced. Although it can be selected, it is preferably 3 parts by weight or more and 10 parts by weight or less with respect to 100 parts by weight of the binder resin. If the compounding amount of the release agent is less than 3 parts by weight, the effect of improving the low-temperature fixability and hot offset resistance may not be sufficiently exhibited. When the compounding amount of the release agent exceeds 10 parts by weight, the dispersibility of the release agent in the melt-kneaded product is lowered, and there is a possibility that a toner having a certain performance cannot be obtained stably. Further, there is a possibility that a phenomenon called filming in which the toner is fused in the form of a film (film) on the surface of an image carrier such as a photoreceptor is likely to occur.

  The melting point (Tm) of the release agent is preferably 50 ° C. or higher and 150 ° C. or lower, and more preferably 80 ° C. or lower. If the melting point is less than 50 ° C., the release agent may melt in the developing device and the toner particles may be aggregated or may cause defects such as filming on the surface of the photoreceptor. When the melting point exceeds 150 ° C., the release agent cannot be sufficiently eluted when the toner is fixed on the recording medium, and the effect of improving the hot offset resistance may not be sufficiently exhibited.

(D) Charge Control Agent The toner of the present invention may contain other toner additive components such as a charge control agent in addition to the binder resin, the colorant, and the release agent. By containing a charge control agent, it is possible to impart preferable chargeability to the toner. As the charge control agent, a charge control agent for positive charge control or negative charge control can be used. For example, positive dyes such as nigrosine dyes, basic dyes, quaternary ammonium salts, quaternary phosphonium salts, aminopyrines, pyrimidine compounds, polynuclear polyamino compounds, aminosilanes, nigrosine dyes and derivatives thereof, triphenylmethane derivatives, guanidine salts, and amidine salts. Charge control agents for charge control and, for example, oil-soluble dyes such as oil black and spiron black, metal-containing azo compounds, azo complex dyes, metal salts of naphthenic acid, metal complexes and metal salts of salicylic acid and its derivatives (metal is Chromium, zinc, zirconium, etc.), boron compounds, fatty acid soaps, long-chain alkyl carboxylates, and charge control agents for controlling negative charges such as resin acid soaps.

  One charge control agent can be used alone, or two or more charge control agents can be used in combination. The amount of the charge control agent used is preferably 0.5 parts by weight or more and 5 parts by weight or less with respect to 100 parts by weight of the binder resin, and more preferably 0.5 parts by weight or more with respect to 100 parts by weight of the binder resin. 3 parts by weight or less. If the charge control agent is contained in an amount of more than 5 parts by weight, the carrier may be contaminated and toner scattering may occur. If it is less than 0.5 parts by weight, there is a possibility that sufficient charging characteristics cannot be imparted to the toner.

  In the color toner, it is desirable to use a colorless charge control agent. For example, it is desirable to use a metal complex and a metal salt of salicylic acid and its derivatives.

[Melting and kneading process]
In the melt-kneading step of step S2, the melt-kneaded product is prepared by melt-kneading the mixture prepared in the pre-mixing step and containing 1 to 50 parts by weight of the crystalline resin with respect to 100 parts by weight of the binder resin. Make it. The melt kneading of the mixture is performed by heating to a temperature not lower than the softening point of the binder resin and lower than the thermal decomposition temperature, and the raw materials for the toner other than the binder resin in the binder resin by melting or softening the binder resin. To disperse.

  As a kneader used for melt kneading, a known kneader can be used. For example, a general kneader such as a kneader, a twin-screw extruder, a two-roll mill, a three-roll mill, or a lab blast mill can be used. More specifically, for example, TEM-100B (trade name, manufactured by Toshiba Machine Co., Ltd.), PCM-65 / 87, PCM-30 (all of which are trade names, manufactured by Ikegai Co., Ltd.), etc. Extruder, open roll type kneaders such as MOS320-1800, Needex (all are trade names, manufactured by Mitsui Mining Co., Ltd.), and the like. The mixture of toner raw materials may be melt-kneaded using a plurality of kneaders.

  Among the above-described kneaders, it is particularly preferable to use a two-roll type continuous kneader which is an open roll type continuous kneader. The two-roll type continuous kneader includes a heating roll and a cooling roll having spiral grooves on the surface and rotating inward from each other.

  According to the two-roll type continuous kneader, the toner raw material mixture obtained in the pre-mixing step is supplied to one end of the open roll on the heating roll by a raw material conveying and feeding device composed of a screw feeder, a vibration feeder, and the like. Is done. The supplied mixture is melted by the heat of the heating roll, wound around the surface of the heating roll, and stays with the cooling roll. While the melt staying between both rolls is transported to the other end side (the end side opposite to the supply side) by the rotation of the open roll, it stays in a state where the lump is divided into several humps, A melt-kneaded product is produced by kneading with the shearing force of the roll.

  In a two-roll type continuous kneader, melt kneading of the mixture is usually performed at a low temperature, so that the binder resin does not progress and the high viscosity fluid binder resin is kneaded, resulting in a large compressive force and shear force. Will occur. The pigment and additive are refined by the compressive force and shear force, and the mixture is melt-kneaded while being uniformly dispersed in the binder resin. And the produced melt-kneaded material is discharged | emitted from the other end discharge side of an open roll, and is cooled and solidified.

  Thus, by melt-kneading the mixture using a two-roll type continuous kneader, the dispersibility of the toner raw material is further improved as compared with the case of using another conventional kneader. Therefore, since the uniformity of the crystalline resin in the toner is improved and finely dispersed, it is possible to prevent the light transmittance from being deteriorated. Furthermore, the hot offset resistance due to the filler effect of the crystalline resin can be improved.

[Crushing process]
In the pulverization step of step S3, the melt-kneaded product obtained in the melt-kneading step is cooled and solidified, and then pulverized to produce a pulverized product. That is, the cooled and solidified melt-kneaded product is first roughly pulverized into a coarsely pulverized product having a volume average particle size of about 100 μm to 5 mm, for example, by a hammer mill or a cutting mill. Thereafter, the obtained coarsely pulverized product is further finely pulverized to, for example, a pulverized product having a volume average particle diameter of 15 μm or less. For finely pulverizing coarsely pulverized products, for example, a jet type pulverizer that uses a supersonic jet stream, or a space formed between a rotor (rotor) and a stator (liner) that rotate at high speed. An impact pulverizer that introduces and pulverizes coarsely pulverized material can be used.

  The cooled and solidified melt-kneaded product may be directly pulverized by a jet pulverizer or an impact pulverizer without being coarsely pulverized by a hammer mill or a cutting mill.

[Classification process]
In the classification step of step S4, by using a classifier from the pulverized product produced in the pulverization step, excessively pulverized toner particles (hereinafter sometimes referred to as “over-pulverized product”) and coarse toner particles (hereinafter referred to as “over-pulverized product”). (Sometimes referred to as “coarse”). The excessively pulverized toner particles and coarse toner particles can be recovered and used for reuse in the production of other toners.

  For the classification, a known classifier capable of removing excessively pulverized toner particles and coarse toner particles by classification by centrifugal force or classification by wind force can be used. For example, a swirling wind classifier (rotary wind classifier), etc. Can be used.

  The classification is preferably carried out by appropriately adjusting the classification conditions so that the toner particles obtained after classification have a volume average particle diameter of 3 μm or more and 15 μm or less. In particular, in order to obtain a high-quality image, it is preferable that the volume average particle diameter of the toner particles is 3 μm or more and 9 μm or less, and in order to further improve the image quality, the volume average particle diameter of the toner particles is 5 μm or more and 8 μm or less. It is preferable that If the volume average particle size of the toner particles is less than 3 μm, the particle size of the toner becomes too small, and there is a possibility that high charge and low fluidity may occur. When this high charging and low fluidity occur, it becomes impossible to stably supply the toner to the photoreceptor as the image carrier, and there is a possibility that background fogging and a decrease in image density may occur. When the volume average particle size of the toner particles exceeds 15 μm, the toner particle size is large, so that a high-definition image cannot be obtained. Further, as the toner particle size increases, the specific surface area decreases and the charge amount of the toner decreases. When the charge amount of the toner is small, the toner is not stably supplied to the photoconductor, and there is a possibility that in-machine contamination due to toner scattering occurs. The classification condition to be adjusted is, for example, the rotational speed of the classification rotor in a swirl type wind classifier (rotary type wind classifier).

The obtained toner particles have a loss elastic modulus G ″ (120 ° C.) at 120 ° C. of 10 ⁵ Pa or less, a loss elastic modulus G ″ (200 ° C.) at 200 ° C. of 10 ¹ Pa or more, and a loss at 200 ° C. The loss tangent, which is a value obtained by dividing the elastic modulus G ″ by the storage elastic modulus G ′, is preferably 10 or less.

  By setting the viscoelasticity of the toner particles in the above range, it is possible to sufficiently obtain a fixable temperature range from the lower limit fixing temperature to the hot offset start temperature, which is an index of toner fixability.

When the loss elastic modulus G ″ (120 ° C.) exceeds 10 ⁵ Pa, the viscosity of the toner becomes too high and the low-temperature fixability deteriorates. Further, the loss elastic modulus G ″ (200 ° C.) is less than 10 ¹ Pa. When the loss tangent exceeds 10, the hot offset resistance deteriorates due to insufficient elasticity of the toner.

  The storage elastic modulus G ′ is a value indicating the elasticity of the sample, and the loss elastic modulus G ″ is a value indicating the viscosity of the sample. A loss tangent which is a ratio of the storage elastic modulus G ′ and the loss elastic modulus G ″. (Tan δ) is a value G ″ / G ′ obtained by dividing the loss elastic modulus G ″ by the storage elastic modulus G ′, and represents the ratio of viscosity to elasticity. Usually, since the storage elastic modulus G ′ and loss elastic modulus G ″ of a resin having high meltability such as a binder resin of toner are highly temperature dependent, in the present invention, the frequency (1.0 Hz) and strain (5% The elastic modulus G ′ and the loss elastic modulus G ″ were measured by vibrating the kneaded material in a molten state while changing the temperature under the condition that the temperature was kept constant. Then, from the obtained measurement results, a loss elastic modulus-temperature characteristic curve indicating the relationship between the loss elastic modulus G ″ and temperature and a loss tangent-temperature characteristic curve indicating the relationship between the loss tangent (tan δ) and temperature are obtained, From these graphs, the value of loss elastic modulus G ″ at 120 ° C. and 200 ° C. and the loss tangent (tan δ) at 200 ° C. were determined.

  The temperature condition in the melt-kneading step is preferably about 120 ° C. or more and 200 ° C. or less, which is a temperature range from the softening temperature of the binder resin in the toner to less than the thermal decomposition temperature. The modulus G ′, loss elastic modulus G ″ and loss tangent (tan δ) were determined.

  The toner particles produced as described above have functions such as powder flowability improvement, triboelectric chargeability improvement, heat resistance improvement, long-term storage stability improvement, cleaning property improvement and photoreceptor surface wear property control. An external additive may be mixed. As the external additive, those commonly used in this field can be used, and examples thereof include fine silica powder, fine titanium oxide powder and fine alumina powder. These inorganic fine powders are used for the purpose of hydrophobizing, charging control, etc. Silicone varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, silane coupling agents, silane coupling agents having functional groups, and other organic It is preferable to be treated with a treating agent such as a silicon compound, and one kind can be used alone, or two or more kinds can be used in combination. The addition amount of the external additive is 5 with respect to 100 parts by weight of the toner particles in consideration of the charge amount necessary for the toner, the influence on the abrasion of the photoreceptor due to the addition of the external additive, and the environmental characteristics of the toner. Part by weight or less is preferred.

  The external additive preferably has a number average particle diameter of primary particles of 10 nm to 500 nm. By using an external additive having such a particle size, the effect of improving the fluidity of the toner is more easily exhibited.

  As described above, the method for producing the toner of the present invention is performed before the mixture is prepared by mixing the binder resin and the colorant that include at least the resin as the main component and the crystalline resin including biomass. A mixing step, a melt-kneading step of melt-kneading a mixture containing a crystalline resin in an amount of 1 part by weight to 50 parts by weight with respect to 100 parts by weight of the binder resin, and pulverizing the melt-kneaded product Thus, a pulverization step for producing a pulverized product and a classification step for removing excessively pulverized product and coarse powder from the pulverized product are included.

  As a result, the toner of the present invention, which is considered for the preservation of the global environment, has excellent fixability and storage stability, and has good light transmittance, can be reduced using the simplest equipment among various toner production methods. Can be manufactured at cost.

  As described above, the toner of the present invention in which an external additive is externally added to the toner particles as needed can be used as it is as a one-component developer, or can be mixed with a carrier as a two-component developer. Can be used.

  As the carrier, magnetic particles can be used. Specific examples of the particles having magnetism include metals such as iron, ferrite, and magnetite, and alloys of these metals with metals such as aluminum or lead. Among these, ferrite is preferable.

  Alternatively, a resin-coated carrier in which magnetic particles are coated with a resin, or a resin-dispersed carrier in which magnetic particles are dispersed in a resin may be used as the carrier. Although there is no restriction | limiting in particular as resin which coat | covers the particle | grains which have magnetism, For example, an olefin resin, a styrene resin, a styrene acrylic resin, a silicone resin, ester resin, a fluorine-containing polymer system resin, etc. are mentioned. Further, the resin used for the resin-dispersed carrier is not particularly limited, and examples thereof include styrene acrylic resin, polyester resin, fluorine resin, and phenol resin.

  The shape of the carrier is preferably a spherical shape or a flat shape. Further, the volume average particle diameter of the carrier is not particularly limited, but is preferably 10 μm to 100 μm, more preferably 50 μm or less in consideration of high image quality.

  As described above, by setting the volume average particle diameter of the carrier to 50 μm or less, the contact opportunity between the toner and the carrier is increased, and charging of each toner particle can be appropriately controlled, so that non-image area fog does not occur. In addition, high-quality images can be achieved.

Furthermore, the resistivity of the carrier is preferably 10 ⁸ Ω · cm or more, more preferably 10 ¹² Ω · cm or more. The carrier resistivity is determined by placing the carrier in a container having a cross-sectional area of 0.50 cm ² and tapping it, then applying a load of 1 kg / cm ² to the particles packed in the container and placing the load between the load and the bottom electrode. This is a value obtained by reading a current value when a voltage generating an electric field of 1000 V / cm is applied. When the resistivity is low, when a bias voltage is applied to the developing sleeve, charges are injected into the carrier, and carrier particles easily adhere to the photoreceptor. In addition, breakdown of the bias voltage is likely to occur.

  The magnetization strength (maximum magnetization) of the carrier is preferably 10 emu / g to 60 emu / g, more preferably 15 emu / g to 40 emu / g. The magnetization strength depends on the magnetic flux density of the developing roller, but under the general magnetic flux density conditions of the developing roller, if it is less than 10 emu / g, the magnetic binding force does not work and causes carrier scattering. There is a fear. On the other hand, if the magnetization strength exceeds 60 emu / g, it is difficult to maintain a non-contact state with the image carrier in the non-contact development in which the carrier spikes are too high. Further, in the contact development, there is a risk that a sweep is likely to appear in the toner image.

The ratio of the toner and the carrier used in the two-component developer is not particularly limited and can be appropriately selected according to the type of the toner and the carrier, but an example is a resin-coated carrier (density 5 g / cm ^{2 to} 8 g / cm ² ). For example, the toner may be used so that the toner is contained in 2% to 30% by weight, preferably 2% to 20% by weight of the total amount of the developer. In the two-component developer, the carrier coverage with the toner is preferably 40% to 80%.

  The two-component developer of the present invention includes the toner of the present invention and a carrier, so that consideration is given to global environmental conservation, excellent fixability and storage stability, and excellent light transmittance. Can be obtained.

[Image forming apparatus]
FIG. 2 is a cross-sectional view schematically showing the configuration of the image forming apparatus 1 of the present invention. The image forming apparatus 1 is a multifunction machine having both a copying function, a printer function, and a facsimile function, and forms a full-color or monochrome image on a recording medium in accordance with transmitted image information. That is, the image forming apparatus 1 has three types of printing modes, ie, a copier mode (copy mode), a printer mode, and a FAX mode, and an operation input from an operation unit (not shown), a personal computer, a portable terminal device, information A print mode is selected by a control unit (not shown) in response to reception of a print job from an external device using a recording storage medium or a memory device. The image forming apparatus 1 includes a toner image forming unit 2, a transfer unit 3, a fixing unit 4, a recording medium supply unit 5, and a discharge unit 6. Each member constituting the toner image forming unit 2 and some members included in the intermediate transfer unit 3 are black (b), cyan (c), magenta (m), and yellow (y) included in the color image information. In order to correspond to the image information of each color, four each are provided. Here, each member provided by four according to each color is distinguished by attaching an alphabet representing each color to the end of the reference symbol, and when referring collectively, only the reference symbol is used.

  The toner image forming unit 2 includes a photosensitive drum 11, a charging unit 12, an exposure unit 13, a developing unit 14, and a cleaning unit 15. The charging unit 12, the developing unit 14, and the cleaning unit 15 are arranged around the photosensitive drum 11 in this order. The charging unit 12 is disposed below the developing unit 14 and the cleaning unit 15 in the vertical direction.

  The photosensitive drum 11 is supported by a driving unit (not shown) so as to be rotatable around an axis, and includes a conductive substrate (not shown) and a photosensitive layer formed on the surface of the conductive substrate. The conductive substrate can take various shapes, and examples thereof include a cylindrical shape, a columnar shape, and a thin film sheet shape. Among these, a cylindrical shape is preferable. The conductive substrate is formed of a conductive material. As the conductive material, those commonly used in this field can be used. For example, metals such as aluminum, copper, brass, zinc, nickel, stainless steel, chromium, molybdenum, vanadium, indium, titanium, gold, platinum, etc. A conductive layer made of one or more of aluminum, aluminum alloy, tin oxide, gold, indium oxide and the like is formed on a film-like substrate such as two or more alloys, a synthetic resin film, a metal film, and paper. And a resin composition containing at least conductive particles or a conductive polymer. In addition, as a film-form base | substrate used for an electroconductive film, a synthetic resin film is preferable and a polyester film is especially preferable. Moreover, as a formation method of the electroconductive layer in an electroconductive film, vapor deposition, application | coating, etc. are preferable.

  The photosensitive layer is formed, for example, by laminating a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material. In that case, it is preferable to provide an undercoat layer between the conductive substrate and the charge generation layer or the charge transport layer. By providing a subbing layer, the surface of the conductive substrate is covered with scratches and irregularities to smooth the surface of the photosensitive layer, preventing deterioration of the chargeability of the photosensitive layer during repeated use, at least at low temperature or low humidity The advantage of improving the charging characteristics of the photosensitive layer under the environment can be obtained. Further, a laminated photoreceptor having a three-layer structure having a high durability and having a photoreceptor surface protective layer as the uppermost layer may be used.

  The charge generation layer is mainly composed of a charge generation material that generates a charge when irradiated with light, and contains a known binder resin, plasticizer, sensitizer and the like as necessary. As the charge generation material, those commonly used in this field can be used, for example, perylene pigments such as perylene imide and perylene acid anhydride, polycyclic quinone pigments such as quinacridone and anthraquinone, metal and metal-free phthalocyanines, and halogenated compounds. Phthalocyanine pigments such as metal-free phthalocyanine, squalium dye, azulenium dye, thiapyrylium dye, carbazole skeleton, styryl stilbene skeleton, triphenylamine skeleton, dibenzothiophene skeleton, oxadiazole skeleton, fluorenone skeleton, bis-stilbene skeleton, distyryl oxa And azo pigments having a diazole skeleton or a distyrylcarbazole skeleton. Among these, metal-free phthalocyanine pigments, oxotitanyl phthalocyanine pigments, bisazo pigments containing at least a fluorene ring or a fluorenone ring, bisazo pigments composed of aromatic amines, trisazo pigments, etc. have high charge generating ability and are highly sensitive. Suitable for obtaining layers. One type of charge generating material can be used alone, or two or more types can be used in combination. The content of the charge generation material is not particularly limited, but is preferably 5 parts by weight to 500 parts by weight, more preferably 10 parts by weight to 200 parts by weight with respect to 100 parts by weight of the binder resin in the charge generation layer. As the binder resin for the charge generation layer, those commonly used in this field can be used. For example, melamine resin, epoxy resin, silicone resin, polyurethane resin, acrylic resin, vinyl chloride-vinyl acetate copolymer resin, polycarbonate, phenoxy Examples thereof include resins, polyvinyl butyral, polyarylate, polyamide, and polyester. Binder resin can be used individually by 1 type, or can use 2 or more types together as needed.

  The charge generation layer generates charge by dissolving or dispersing appropriate amounts of charge generation materials, binder resins and, if necessary, plasticizers and sensitizers in an appropriate organic solvent capable of dissolving or dispersing these components. It can be formed by preparing a layer coating solution, applying this charge generation layer coating solution to the surface of the conductive substrate and drying. The film thickness of the charge generation layer thus obtained is not particularly limited, but is preferably 0.05 μm to 5 μm, more preferably 0.1 μm to 2.5 μm.

  The charge transport layer laminated on the charge generation layer has a charge transport material having the ability to accept and transport the charge generated from the charge generation material and a binder resin for the charge transport layer as essential components. Contains known antioxidants, plasticizers, sensitizers, lubricants and the like. As the charge transport material, those commonly used in this field can be used, for example, poly-N-vinylcarbazole and derivatives thereof, poly-γ-carbazolylethyl glutamate and derivatives thereof, pyrene-formaldehyde condensation product and derivatives thereof, Polyvinylpyrene, polyvinylphenanthrene, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, 9- (p-diethylaminostyryl) anthracene, 1,1-bis (4-dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline, pyrazoline Derivatives, phenylhydrazones, hydrazone derivatives, triphenylamine compounds, tetraphenyldiamine compounds, triphenylmethane compounds, stilbene compounds, 3-methyl-2-benzothiazoline -Donating substances such as azine compounds, fluorenone derivatives, dibenzothiophene derivatives, indenothiophene derivatives, phenanthrenequinone derivatives, indenopyridine derivatives, thioxanthone derivatives, benzo [c] cinnoline derivatives, phenazine oxide derivatives, tetracyano Examples include electron-accepting substances such as ethylene, tetracyanoquinodimethane, promanyl, chloranil, and benzoquinone. The charge transport materials can be used alone or in combination of two or more. The content of the charge transport material is not particularly limited, but is preferably 10 parts by weight to 300 parts by weight, more preferably 30 parts by weight to 150 parts by weight with respect to 100 parts by weight of the binder resin in the charge transport material. As the binder resin for the charge transport layer, those commonly used in this field and capable of uniformly dispersing the charge transport material can be used. For example, polycarbonate, polyarylate, polyvinyl butyral, polyamide, polyester, polyketone, epoxy resin, polyurethane , Polyvinyl ketone, polystyrene, polyacrylamide, phenol resin, phenoxy resin, polysulfone resin, and copolymer resins thereof. Among these, in consideration of film formability, wear resistance of the resulting charge transport layer, electrical characteristics, etc., polycarbonate containing bisphenol Z as a monomer component (hereinafter referred to as “bisphenol Z type polycarbonate”), bisphenol Z type polycarbonate And a mixture of polycarbonate with other polycarbonates are preferred. Binder resin can be used individually by 1 type, or can use 2 or more types together.

  The charge transport layer preferably contains an antioxidant together with the charge transport material and the binder resin for the charge transport layer. As the antioxidant, those commonly used in this field can be used, and examples thereof include vitamin E, hydroquinone, hindered amine, hindered phenol, paraphenylenediamine, arylalkane and derivatives thereof, organic sulfur compounds, and organic phosphorus compounds. It is done. One antioxidant can be used alone, or two or more antioxidants can be used in combination. The content of the antioxidant is not particularly limited, but is 0.01% to 10% by weight, preferably 0.05% to 5% by weight, based on the total amount of components constituting the charge transport layer. The charge transport layer is dissolved or dispersed in a suitable organic solvent that can dissolve or disperse these components in an appropriate amount such as a charge transport material and a binder resin, and if necessary, an antioxidant, a plasticizer, and a sensitizer. The charge transport layer coating liquid is prepared, and the charge transport layer coating liquid is applied to the surface of the charge generation layer and dried. The thickness of the charge generation layer thus obtained is not particularly limited, but is preferably 10 μm to 50 μm, more preferably 15 μm to 40 μm. Note that a photosensitive layer in which a charge generation material and a charge transport material are present can be formed in one layer. In that case, the type, content, binder resin, and other additives of the charge generation material and the charge transport material may be the same as in the case of separately forming the charge generation layer and the charge transport layer.

  In this embodiment, the photosensitive drum formed by forming the organic photosensitive layer using the charge generation material and the charge transport material as described above is used. Instead, an inorganic photosensitive layer using silicon or the like is formed. Can be used.

  The charging unit 12 faces the photosensitive drum 11 and is arranged so as to be separated from the surface of the photosensitive drum 11 along the longitudinal direction of the photosensitive drum 11 with a gap, and the surface of the photosensitive drum 11 has a predetermined polarity and Charge to potential. As the charging unit 12, a charging brush type charger, a charger type charger, a sawtooth type charger, an ion generator, or the like can be used. In the present embodiment, the charging unit 12 is provided so as to be separated from the surface of the photosensitive drum 11, but is not limited thereto. For example, a charging roller may be used as the charging unit 12 and the charging roller may be disposed so that the charging roller and the photosensitive drum are in pressure contact with each other, or a contact charging type charger such as a charging brush or a magnetic brush may be used. .

  The exposure unit 13 is arranged such that light of each color information emitted from the exposure unit 13 passes between the charging unit 12 and the developing unit 14 and is irradiated on the surface of the photosensitive drum 11. The exposure unit 13 branches the image information into light of each color information of b, c, m, and y in the unit, and the surface of the photosensitive drum 11 charged to a uniform potential by the charging unit 12 is light of each color information. To form an electrostatic latent image on the surface. As the exposure unit 13, for example, a laser scanning unit including a laser irradiation unit and a plurality of reflecting mirrors can be used. In addition, a unit in which an LED array, a liquid crystal shutter, and a light source are appropriately combined may be used.

  FIG. 3 is a cross-sectional view schematically showing an example of the configuration of the developing device 14 of the present invention. The developing unit 14 includes a developing tank 20 and a toner hopper 21. The developing tank 20 is disposed so as to face the surface of the photosensitive drum 11, and is a container that supplies toner to the electrostatic latent image formed on the surface of the photosensitive drum 11 and develops it to form a visible toner image. It is a shaped member. The developing tank 20 contains toner in its internal space, and contains a roller member such as the developing roller 20a, the supply roller 20b, and the stirring roller 20c or a screw member, and rotatably supports the developing tank 20. An opening is formed in a side surface of the developing tank 20 facing the photosensitive drum 11, and a developing roller 20 a is rotatably provided at a position facing the photosensitive drum 11 through the opening. The developing roller 20 a is a roller-like member that supplies toner to the electrostatic latent image on the surface of the photoconductor 11 at the pressure contact portion or the closest portion with the photoconductor drum 11. When supplying the toner, a potential having a polarity opposite to the charging potential of the toner is applied to the surface of the developing roller 20a as a developing bias voltage (hereinafter simply referred to as “developing bias”). As a result, the toner on the surface of the developing roller 20a is smoothly supplied to the electrostatic latent image. Further, by changing the developing bias value, the amount of toner (toner adhesion amount) supplied to the electrostatic latent image can be controlled. The supply roller 20b is a roller-like member provided so as to be rotatable and facing the developing roller 20a, and supplies toner around the developing roller 20a. The agitation roller 20c is a roller-like member provided so as to be able to rotate and face the supply roller 20b, and feeds toner newly supplied from the toner hopper 21 into the developing tank 20 to the periphery of the supply roller 20b. The toner hopper 21 is provided so that a toner replenishing port (not shown) provided at the lower part in the vertical direction communicates with a toner receiving port (not shown) provided at the upper part in the vertical direction of the developing tank 20. The toner is replenished according to the toner consumption status of 20. Further, the toner hopper 21 may not be used, and the toner may be directly supplied from each color toner cartridge.

  The cleaning unit 15 removes the toner remaining on the surface of the photosensitive drum 11 after transferring the toner image to the recording medium, and cleans the surface of the photosensitive drum 11. For the cleaning unit 15, for example, a plate-like member such as a cleaning blade is used. In the image forming apparatus 1 of the present invention, an organic photosensitive drum is mainly used as the photosensitive drum 11, and the surface of the organic photosensitive drum is mainly composed of a resin component. Surface degradation is likely to proceed due to the chemical action of ozone generated by the discharge. However, the deteriorated surface portion is worn by receiving a rubbing action by the cleaning unit 15 and is gradually but surely removed. Therefore, the problem of surface deterioration due to ozone or the like is practically solved, and the charging potential by the charging operation can be stably maintained over a long period of time. Although the cleaning unit 15 is provided in this embodiment, the present invention is not limited to this, and the cleaning unit 15 may not be provided.

  According to the toner image forming unit 2, the surface of the photosensitive drum 11 that is uniformly charged by the charging unit 12 is irradiated with signal light corresponding to the image information from the exposure unit 13 to form an electrostatic latent image. Toner is supplied from the developing means 14 to form a toner image, and after the toner image is transferred to the intermediate transfer belt 25, the toner remaining on the surface of the photosensitive drum 11 is removed by the cleaning unit 15. This series of toner image forming operations is repeatedly executed.

  The transfer unit 3 is disposed above the photosensitive drum 11, and includes an intermediate transfer belt 25, a driving roller 26, a driven roller 27, an intermediate transfer roller 28 (b, c, m, y), and a transfer belt cleaning unit. 29 and the transfer roller 30. The intermediate transfer belt 25 is an endless belt-like member that is stretched by a driving roller 26 and a driven roller 27 to form a loop-shaped movement path, and the direction of the arrow B, that is, the surface in contact with the photosensitive drum 11 is photosensitive. It is rotationally driven so as to move in the direction from the body drum 11y to 11b.

  When the intermediate transfer belt 25 passes through the photosensitive drum 11 while being in contact with the photosensitive drum 11, an intermediate transfer roller 28 disposed on the surface of the photosensitive drum 11 is opposed to the photosensitive drum 11 via the intermediate transfer belt 25. A transfer bias having a polarity opposite to the charging polarity of the toner is applied, and the toner image formed on the surface of the photosensitive drum 11 is transferred onto the intermediate transfer belt 25. In the case of a full-color image, each color toner image formed on each photoconductor drum 11 is sequentially transferred onto the intermediate transfer belt 25 to form a full-color toner image. The driving roller 26 is provided so as to be rotatable around its axis by driving means (not shown), and the intermediate transfer belt 25 is driven to rotate in the direction of arrow B by the rotational driving. The driven roller 27 is provided so as to be able to be driven and rotated by the rotational drive of the driving roller 26, and applies a certain tension to the intermediate transfer belt 25 so that the intermediate transfer belt 25 does not loosen. The intermediate transfer roller 28 is provided in pressure contact with the photosensitive drum 11 via the intermediate transfer belt 25 and capable of being driven to rotate about its axis by a driving unit (not shown). The intermediate transfer roller 28 is connected to a power source (not shown) for applying a transfer bias as described above, and has a function of transferring the toner image on the surface of the photosensitive drum 11 to the intermediate transfer belt 25. The transfer belt cleaning unit 29 is provided so as to face the driven roller 27 through the intermediate transfer belt 25 and to contact the outer peripheral surface of the intermediate transfer belt 25. Since the toner adhering to the intermediate transfer belt 25 due to contact with the photosensitive drum 11 causes the back surface of the recording medium to be contaminated, the transfer belt cleaning unit 29 removes and collects the toner on the surface of the intermediate transfer belt 25. The transfer roller 30 is provided in pressure contact with the drive roller 26 via the intermediate transfer belt 25, and can be driven to rotate about an axis by a drive unit (not shown). At the pressure contact portion (transfer nip portion) between the transfer roller 30 and the drive roller 26, the toner image carried and conveyed by the intermediate transfer belt 25 is transferred to the recording medium fed from the recording medium supply means 5 described later. Is done. The recording medium carrying the toner image is fed to the fixing unit 4. According to the transfer unit 3, the toner image transferred from the photosensitive drum 11 to the intermediate transfer belt 25 at the pressure contact portion between the photosensitive drum 11 and the intermediate transfer roller 28 rotates the intermediate transfer belt 25 in the arrow B direction. It is conveyed to a transfer nip portion by driving, and transferred to a recording medium there.

  The fixing unit 4 is provided downstream of the transfer unit 3 in the conveyance direction of the recording medium, and includes a fixing roller 31 and a pressure roller 32. The fixing roller 31 is rotatably provided by a driving unit (not shown), and heats and fixes a toner image formed on the recording medium. A heating unit (not shown) is provided inside the fixing roller 31. The heating unit heats the fixing roller 31 so that the surface of the fixing roller 31 reaches a predetermined temperature (heating temperature). For example, a heater or a halogen lamp can be used as the heating means. The heating means is controlled by fixing condition control means described later. A temperature detection sensor is provided near the surface of the fixing roller 31 to detect the surface temperature of the fixing roller 31. The detection result by the temperature detection sensor is written in the storage unit of the control means described later. The pressure roller 32 is provided so as to be in pressure contact with the fixing roller 31 and is supported so as to be driven to rotate by the rotation drive of the pressure roller 32. The pressure roller 32 assists fixing of the toner image on the recording medium by pressing the toner and the recording medium when the toner is melted and fixed on the recording medium by the fixing roller 31. A pressure contact portion between the fixing roller 31 and the pressure roller 32 is a fixing nip portion. According to the fixing unit 4, the recording medium onto which the toner image is transferred by the transfer unit 3 is sandwiched between the fixing roller 31 and the pressure roller 32, and the toner image is recorded under heating when passing through the fixing nip portion. By being pressed against the medium, the toner image is fixed on the recording medium, and a fixed image is formed.

  The recording medium supply unit 5 includes an automatic paper feed tray 35, a pickup roller 36, a transport roller 37, a registration roller 38, and a manual paper feed tray 39. The automatic paper feed tray 35 is a container-like member that is provided in the lower part of the image forming apparatus 1 in the vertical direction and stores a recording medium. Recording media include plain paper, color copy paper, overhead projector sheets, postcards, and the like. The pick-up roller 36 takes out the recording medium stored in the automatic paper feed tray 35 one by one and feeds it to the paper transport path S1. The conveyance rollers 37 are a pair of roller members provided so as to be in pressure contact with each other, and convey the recording medium toward the registration rollers 38. The registration rollers 38 are a pair of roller members provided so as to be in pressure contact with each other, and the recording medium fed from the conveyance roller 37 is used to convey the toner image carried on the intermediate transfer belt 25 to the transfer nip portion. Synchronously, it is fed to the transfer nip. The manual paper feed tray 39 is a device for taking a recording medium into the image forming apparatus 1 by manual operation, and the recording medium taken from the manual paper feed tray 39 passes through the paper conveyance path S2 by the conveyance roller 37. Then, it is fed to the registration roller 38. According to the recording medium supply means 5, the toner image carried on the intermediate transfer belt 25 is conveyed to the transfer nip portion of the recording medium supplied one by one from the automatic paper feed tray 35 or the manual paper feed tray 39. In synchronism with this, the sheet is fed to the transfer nip portion.

  The discharge unit 6 includes a conveyance roller 37, a discharge roller 40, and a discharge tray 41. The conveyance roller 37 is provided downstream of the fixing nip portion in the sheet conveyance direction, and conveys the recording medium on which the image is fixed by the fixing unit 4 toward the discharge roller 40. The discharge roller 40 discharges the recording medium on which the image is fixed to a discharge tray 41 provided on the upper surface in the vertical direction of the image forming apparatus. The discharge tray 41 stores a recording medium on which an image is fixed.

The image forming apparatus 1 includes a control unit (not shown). The control means is provided, for example, in the upper part of the internal space of the image forming apparatus 1 and includes a storage unit, a calculation unit, and a control unit. The storage unit of the control unit includes various setting values via an operation panel (not shown) arranged on the upper surface of the image forming apparatus 1, detection results from sensors (not shown) arranged at various locations inside the image forming apparatus 1, external devices, and the like. The image information from is input. In addition, programs for executing various means are written. Examples of the various means include a recording medium determination unit, an adhesion amount control unit, and a fixing condition control unit. As the storage unit, those commonly used in this field can be used, and examples thereof include a read only memory (ROM), a random access memory (RAM), and a hard disk drive (HDD). As the external device, an electric / electronic device that can form or acquire image information and can be electrically connected to the image forming apparatus 1 can be used. For example, a computer, a digital camera, a television receiver, a video recorder , DVD (Digital
Examples include a Versatile Disc (Recorder), HDDVD (High-Definition Digital Versatile Disc), Blu-ray Disc recorder, facsimile machine, and portable terminal device. The arithmetic unit takes out various data (image formation command, detection result, image information, etc.) written in the storage unit and programs of various means, and performs various determinations. The control unit sends a control signal to the corresponding device according to the determination result of the calculation unit, and performs operation control. The control unit and the calculation unit include a processing circuit realized by a microcomputer, a microprocessor, or the like provided with a central processing unit (CPU). The control means includes a main power supply together with the processing circuit described above, and the power supply supplies power not only to the control means but also to each device in the image forming apparatus 1.

  Thus, the developing device 14 of the present invention can maintain the storage stability while ensuring the toner fixability by performing development using the toner or the two-component developer of the present invention. Stable performance can be maintained against stress such as stirring in the developing tank.

  Further, the image forming apparatus 1 according to the present invention includes the developing device 14 according to the present invention, so that a stable high-quality image excellent in fixability and color developability can be formed without causing trouble over a long period of time. it can.

  In addition, the image forming apparatus 1 of the present invention preferably includes a fixing unit 4 that melts and fixes a toner image formed on a recording medium. As described above, by using the toner of the present invention to form a fixed image by the image forming apparatus 1 including the fixing unit 4 as described above, it is possible to effectively draw out toner physical properties that achieve both low-temperature fixability and storage stability. High-quality images can be obtained.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. However, the present invention is not particularly limited to these Examples as long as the gist thereof is not exceeded.

[Physical property measurement method]
Each physical property value in Examples and Comparative Examples was measured as shown below.

[Glass transition temperature of binder resin (Tg)]
Using a differential scanning calorimeter (trade name: Diamond DSC, manufactured by PerkinElmer Japan Co., Ltd.), a sample 0.01 g was heated at a heating rate of 10 ° C. per minute (10 ° C./min) according to Japanese Industrial Standard (JIS) K7121-1987. ) And the DSC curve was measured. The intersection of the straight line obtained by extending the low-temperature base line of the endothermic peak corresponding to the glass transition of the obtained DSC curve to the high-temperature side and the tangent line drawn at the point where the slope is maximum with respect to the low-temperature curve of the peak. The temperature was determined as the glass transition temperature (Tg).

[Softening temperature (T _1/2 )]
Using a flow characteristic evaluation apparatus (trade name: Flow Tester CFT-500C, manufactured by Shimadzu Corporation), 1 g of a sample is inserted into a cylinder, and a load of 10 kgf / cm ² (0.980665 MPa) is applied so as to be extruded from a die. While heating at a heating rate of 6 ° C./min (6 ° C./min), the temperature at which half of the sample flowed out of the die was determined as the softening temperature. A die having a diameter of 1 mm and a length of 1 mm was used.

[Peak Top Molecular Weight, Weight Average Molecular Weight (Mw) and Molecular Weight Distribution Index (Mw / Mn)]
Using a GPC apparatus (trade name: HLC-8220 GPC, manufactured by Tosoh Corporation), at a temperature of 40 ° C., a 0.25 wt% tetrahydrofuran (hereinafter referred to as “THF”) solution of the sample was used as the sample solution. The molecular weight distribution curve was determined with an injection volume of 200 μL. The molecular weight at the peak of the obtained molecular weight distribution curve was determined as the peak top molecular weight. Further, from the obtained molecular weight distribution curve, a weight average molecular weight Mw and a number average molecular weight Mn are obtained, and a molecular weight distribution index (Mw / Mn; hereinafter, simply “Mw / Mn”) which is a ratio of the weight average molecular weight Mw to the number average molecular weight Mn. ). The molecular weight calibration curve was prepared using standard polystyrene.

[Acid value]
The acid value was measured by neutralization titration as follows. A sample of 5 g was dissolved in 50 mL of THF, and several drops of an ethanol solution of phenolphthalein was added as an indicator, followed by titration with a 0.1 mol / L potassium hydroxide (KOH) aqueous solution. The point at which the color of the sample solution changed from colorless to purple was used as the end point, and the acid value (mgKOH / g) was calculated from the amount of potassium hydroxide aqueous solution required to reach the end point and the weight of the sample subjected to titration. .

[THF insoluble matter in binder resin]
1 g of the sample was put into a cylindrical filter paper, passed through a Soxhlet extractor, heated and refluxed for 6 hours using 100 mL of THF as a solvent, and components soluble in THF in the sample were extracted with THF. After removing the solvent from the extracted extract containing the THF-soluble matter, the THF-soluble matter was dried at 100 ° C. for 24 hours, and the weight X (g) of the obtained THF-soluble matter was weighed. Based on the obtained weight X (g) of the THF soluble content and the weight of the sample used for the measurement (1 g), based on the following formula (2), the THF insoluble component which is insoluble in THF in the binder resin The ratio P (% by weight) of the minutes was calculated. Hereinafter, this ratio P is described as THF insoluble matter.
P (% by weight) = {1 (g) −X (g)} / 1 (g) × 100 (2)

[Melting point (Tm)]
Using a differential scanning calorimeter (trade name: Diamond DSC, manufactured by Perkin Elmer Japan Co., Ltd.), according to Japanese Industrial Standard (JIS) K7121-1987, 0.01 g of a sample was obtained at a temperature of 20 ° C. to 200 ° C. per minute at 10 ° C. The temperature was raised at a rate of 50 ° C. per minute from 200 ° C. to 20 ° C., and then heated again at a rate of 10 ° C. per minute from 20 ° C. to 200 ° C. About the peak of the heat of fusion of the DSC curve obtained, the temperature at the top of the peak was determined as the melting point (Tm).

[Viscoelasticity of toner]
The storage elastic modulus G ′ and the loss elastic modulus G ″ were measured with a stress rheometer (manufactured by REOLOGICA Instruments AB) using a parallel plate as follows. 25 ° C.) and a pressure of about 20 MPa for 1 minute to prepare a measurement sample having a thickness of about 0.5 mm and a diameter of 25 mm, which is sandwiched between parallel plates having a diameter of 25 mm, heated and melted. The sample for measurement is sine-wave oscillated by setting the interval between the parallel plates to 1.0 mm, giving a strain that vibrates sinusoidally in the circumferential direction of the parallel plate under the conditions of 5% strain and 1.0 Hz. Storage temperature at each temperature at a measurement temperature interval of 10 ° C. with a temperature increase rate of 3 ° C./min from 80 ° C. to 200 ° C. It was measured G 'and loss modulus G ". Then, from the obtained measurement results, the loss elastic modulus-temperature characteristic curve showing the relationship between the loss elastic modulus G ″ and the temperature and the loss tangent showing the relationship between the loss tangent (tan δ, G ″ / G ′) and the temperature— Temperature characteristic curves were obtained, and from these graphs, values of loss elastic modulus G ″ and loss tangent (tan δ) at 120 ° C. and 200 ° C. were obtained.

[Particle size distribution (volume average particle diameter (D _50v ) and coefficient of variation (CV value) of toner)]
20 ml of a sample and 1 ml of sodium alkyl ether sulfate (dispersant, manufactured by Kishida Chemical Co., Ltd.) are added to 50 ml of an electrolytic solution (trade name: ISOTON-II, manufactured by Beckman Coulter), and an ultrasonic dispersion device (trade name: UH-50, manufactured by SMT Co., Ltd.) was subjected to ultrasonic dispersion treatment at an ultrasonic frequency of 20 kHz for 3 minutes as a measurement sample. For this measurement sample, a particle size distribution measuring device (trade name: Multisizer 3, manufactured by Beckman Coulter, Inc.) was used to measure the particle diameter of the sample particles under the conditions of an aperture diameter of 20 μm and a measurement particle number of 50000 counts. The volume particle size distribution of the sample particles was determined from the measured results, and the volume average particle size D _{50 V} (μm) was calculated from the determined volume particle size distribution. Moreover, the standard deviation in volume particle size distribution was calculated | required, and the variation coefficient (CV value,%) was computed based on following formula (3). The volume average particle size D _50V (μm) indicates a particle size at which the cumulative volume from the large particle size side in the cumulative volume distribution becomes 50%.
CV value (%) = {standard deviation in volume particle size distribution / volume average particle size (μm)} × 100
... (3)

Example 1
[Pre-mixing process]
As binder resin (100 parts by weight), polyester resin A as a main component (glass transition temperature (Tg): 60 ° C., softening temperature (T _1/2 ): 110 ° C., peak top molecular weight 12500, Mw / Mn = 5 .2, acid value 16, THF insoluble content 0%) 81.5% by weight (90.0 parts by weight) and polylactic acid resin A (trade name: Terramac TE-2000C, manufactured by Unitika Ltd., melting point (Tm): 170 ° C) 9.0% by weight (10.0 parts by weight) and KET. BLUE111 (trade name: copper phthalocyanine 15: 3, manufactured by Clariant) 5.0% by weight (5.5 parts by weight) and paraffin wax (trade name: HNP-10, manufactured by Nippon Seiwa Co., Ltd.) Melting point (Tm): 75 ° C.) 3.0% by weight (3.3 parts by weight) and charge control agent (trade name: Copy Charge N4P VP 2481, manufactured by Clariant Japan KK) 1.5% by weight (1.7) The toner raw material containing 2 parts by weight) was mixed for 3 minutes with a Henschel mixer (trade name: FM20C, manufactured by Mitsui Mining Co., Ltd.) to obtain a mixture.

[Melting and kneading process]
20.0 kg of the mixture was melt kneaded with an open roll type (two roll type) continuous kneader (trade name: MOS320-1800, manufactured by Mitsui Mining Co., Ltd.) to prepare a melt kneaded product. The setting conditions of the open roll at this time were a heating roll supply side temperature of 140 ° C., a discharge side temperature of 70 ° C., a cooling roll supply side temperature of 80 ° C., and a discharge side temperature of 15 ° C. As the heating roll and the cooling roll, a roll having a diameter of 320 mm and an effective length of 1550 mm was used, and the gap between the rolls on the supply side and the discharge side was 0.3 mm. Moreover, the rotation speed of the heating roll was 75 rpm, the rotation speed of the cooling roll was 65 rpm, and the supply amount of the mixture was 30 kg / h.

[Crushing classification process]
The melt-kneaded product obtained in the melt-kneading step was cooled to room temperature and solidified, and then coarsely pulverized with a cutter mill (trade name: VM-16, manufactured by Orient Corporation). Next, the coarsely pulverized product obtained by the coarse pulverization was finely pulverized by a counter jet mill (trade name: AFG, manufactured by Hosokawa Micron Corporation), and the obtained pulverized product was then subjected to a rotary classifier (trade name: TSP separator, Hosokawa Micron). The toner particles were obtained by classifying the particles by removing the excessively pulverized toner particles.

The obtained toner particles have a loss elastic modulus G ″ at 120 ° C. of 5.4 × 10 ⁴ Pa, a loss elastic modulus G ″ at 200 ° C. of 2.5 × 10 ² Pa, and 200 The value of loss tangent (tan δ) at ° C. was 4.1. The temperature at which the loss elastic modulus G ″ of the toner particles at a frequency of 1 Hz is 10 ³ Pa is 160 ° C., and the melting point (Tm) of the polylactic acid resin A is 10 ° C. higher.

Next, 0.2 part by weight of hydrophobic silica (trade name: R-974, manufactured by Nippon Aerosil Co., Ltd.) and hydrophobic titanium (trade name: T-805, Japan) with respect to 100 parts by weight of the obtained toner particles. 16.8 kg of the toner of Example 1 was manufactured by adding 0.3 part by weight of Aerosil Co., Ltd. and mixing with a Henschel mixer (trade name: FM mixer, manufactured by Mitsui Mining Co., Ltd.).
The obtained toner had a volume average particle diameter of 6.7 μm and a coefficient of variation (CV value) of 23%.

(Example 2)
In the pre-mixing step, as the binder resin (100 parts by weight), the main components of polyester resin A 72.4% by weight (80.0 parts by weight) and polylactic acid resin A 18.1% by weight (20.0 parts by weight) 16.0 kg of the toner of Example 2 was produced in the same manner as in Example 1 except that it was used.

The obtained toner particles have a loss elastic modulus G ″ at 120 ° C. of 7.8 × 10 ⁴ Pa and a loss elastic modulus G ″ at 200 ° C. of 3.2 × 10 ² Pa. The value of loss tangent (tan δ) at ° C. was 3.2. The temperature at which the loss elastic modulus G ″ of the toner particles at a frequency of 1 Hz becomes 10 ³ Pa is 164 ° C., and the melting point (Tm) of the polylactic acid resin A is 6 ° C. higher. The volume average particle diameter of the toner is 6.8 μm, and the coefficient of variation (CV value) is 25%.

(Example 3)
[Production of polylactic acid resin B]
47.5 kg of L-lactide and 2.5 kg of D-lactide were charged into the polymerization reaction layer, heated and melted with stirring under a nitrogen atmosphere, and uniformly mixed. Next, after adding 15 g of tin octylate, the mixture was heated to 190 ° C. and subjected to ring-opening polymerization for 3 hours until the viscosity of the reaction product became high, and polylactic acid resin B (weight average molecular weight (Mw): 12000, Mw / Mn = 2.7, melting point (Tm): 129 ° C., molar ratio of D-lactic acid unit to L-lactic acid unit: 0.085).

[Production of toner]
In the pre-mixing step, as the binder resin (100 parts by weight), the main components of polyester resin A 54.3% by weight (60.0 parts by weight) and polylactic acid resin B 36.2% by weight (40.0 parts by weight) Except for the use, 14.1 kg of the toner of Example 3 was produced in the same manner as in Example 1.

The obtained toner particles have a loss elastic modulus G ″ at 120 ° C. of 4.3 × 10 ⁴ Pa and a loss elastic modulus G ″ at 200 ° C. of 7.8 × 10 Pa. The value of loss tangent (tan δ) was 6.5. The temperature at which the loss elastic modulus G ″ of the toner particles at a frequency of 1 Hz is 10 ³ Pa is 120 ° C., and the melting point (Tm) of the polylactic acid resin B is 9 ° C. higher. The toner had a volume average particle size of 6.7 μm and a coefficient of variation (CV value) of 24%.

Example 4
[Production of polylactic acid resin C]
Polylactic acid resin C (weight average molecular weight (Mw): 11000) in the same manner as polylactic acid resin B except that the ratio of L-lactide and D-lactide was changed to L-lactide 40 kg and D-lactide 10 kg. Mw / Mn = 2.8, melting point (Tm): 123 ° C., molar ratio of D-lactic acid unit to L-lactic acid unit: 0.2).

[Production of toner]
In the pre-mixing step, 49.8% by weight (55.0 parts by weight) of polyester resin A, which is the main component, and 40.7% by weight (45.0 parts by weight) of polylactic acid resin C are used as the binder resin (100 parts by weight). 15.3 kg of the toner of Example 4 was produced in the same manner as in Example 1 except that it was used.

The obtained toner particles have a loss elastic modulus G ″ at 120 ° C. of 3.2 × 10 ⁴ Pa and a loss elastic modulus G ″ at 200 ° C. of 5.1 × 10 Pa. The value of loss tangent (tan δ) was 7.2. Further, the temperature at which the loss elastic modulus G ″ of the toner particles at a frequency of 1 Hz becomes 10 ³ Pa is 114 ° C., and the melting point (Tm) of the polylactic acid resin C is 9 ° C. higher. The toner had a volume average particle size of 6.5 μm and a coefficient of variation (CV value) of 23%.

(Comparative Example 1)
In the premixing step, as the binder resin (100 parts by weight), polyester resin A 36.2% by weight (40.0 parts by weight) and polylactic acid resin A 54.3% by weight (60.0 parts by weight) as main components were added. A toner was tried in the same manner as in Example 1 except that it was used. However, the toner could not be melt kneaded and the toner of Comparative Example 1 could not be obtained.

(Comparative Example 2)
In the melt-kneading step, 15.1 kg of the toner of Comparative Example 2 was produced in the same manner as in Example 2 except that the mixture was melt-kneaded using an extruder (trade name: PCM-30, manufactured by Ikegai Co., Ltd.). The setting conditions of the extruder at this time were a screw rotation speed of 250 rpm and a discharge amount of 65 kg / h.

The obtained toner particles have a loss elastic modulus G ″ at 120 ° C. of 5.2 × 10 ⁴ Pa and a loss elastic modulus G ″ at 200 ° C. of 7.3 × 10 Pa. The value of loss tangent (tan δ) was 22. The temperature at which the loss elastic modulus G ″ of the toner particles at a frequency of 1 Hz is 10 ³ Pa is 145 ° C., and the melting point (Tm) of the polylactic acid resin A is 25 ° C. higher. The toner had a volume average particle size of 8.8 μm and a coefficient of variation (CV value) of 41%.

(Comparative Example 3)
13.2 kg of the toner of Comparative Example 3 was produced in the same manner as in Example 3 except that in the melt-kneading step, the mixture was melt-kneaded using an extruder (trade name: PCM-30, manufactured by Ikegai Co., Ltd.). The setting conditions of the extruder at this time were a screw rotation speed of 250 rpm and a discharge amount of 65 kg / h.

The obtained toner particles have a loss elastic modulus G ″ at 120 ° C. of 4.7 × 10 ⁴ Pa and a loss elastic modulus G ″ at 200 ° C. of 3.7 × 10 Pa. The value of loss tangent (tan δ) was 15. The temperature at which the loss elastic modulus G ″ of the toner particles at a frequency of 1 Hz becomes 10 ³ Pa is 116 ° C., and the melting point (Tm) of the polylactic acid resin B is 13 ° C. higher. The toner had a volume average particle size of 7.0 μm and a coefficient of variation (CV value) of 31%.

(Comparative Example 4)
In the melt-kneading step, 15.5 kg of toner of Comparative Example 4 was produced in the same manner as in Example 4 except that the mixture was melt-kneaded using an extruder (trade name: PCM-30, manufactured by Ikegai Co., Ltd.). The setting conditions of the extruder at this time were a screw rotation speed of 250 rpm and a discharge amount of 65 kg / h.

The obtained toner particles have a loss elastic modulus G ″ at 120 ° C. of 4.3 × 10 ⁴ Pa, a loss elastic modulus G ″ at 200 ° C. of 8.7 Pa, and a loss tangent at 200 ° C. The value of (tan δ) was 18. Further, the temperature at which the loss elastic modulus G ″ of the toner particles at a frequency of 1 Hz becomes 10 ³ Pa is 108 ° C., and the melting point (Tm) of the polylactic acid resin C is 15 ° C. higher. The toner had a volume average particle size of 6.8 μm and a coefficient of variation (CV value) of 33%.

(Comparative Example 5)
In the pre-mixing step, as the binder resin (100 parts by weight), polyester resin B (glass transition temperature (Tg): 58 ° C., softening temperature (T _1/2 ): 102 ° C. instead of polyester resin A as the main component) The toner of Comparative Example 5 was produced in the same manner as in Example 1 except that a peak top molecular weight of 8500, Mw / Mn = 2.5, an acid value of 13, and a THF-insoluble content of 0% were used.

The obtained toner particles have a loss elastic modulus G ″ at 120 ° C. of 4.5 × 10 ⁴ Pa, a loss elastic modulus G ″ at 200 ° C. of 9.4 Pa, and a loss tangent at 200 ° C. The value of (tan δ) was 35.2. The temperature at which the loss elastic modulus G ″ of the toner particles at a frequency of 1 Hz is 10 ³ Pa is 140 ° C., and the melting point (Tm) of the polylactic acid resin A is 30 ° C. higher. The toner had a volume average particle size of 6.4 μm and a coefficient of variation (CV value) of 32%.

(Comparative Example 6)
In the pre-mixing step, as a binder resin (100 parts by weight), instead of the main component polyester resin A, polyester resin C (glass transition temperature (Tg): 60 ° C., softening temperature (T _1/2 ): 116 ° C. 10.5 kg of the toner of Comparative Example 6 was produced in the same manner as in Example 1 except that a peak top molecular weight of 32100, Mw / Mn = 8.2, acid value of 9, and THF-insoluble content of 4% was used.

The obtained toner particles have a loss elastic modulus G ″ at 120 ° C. of 7.2 × 10 ⁵ Pa, a loss elastic modulus G ″ at 200 ° C. of 1.1 × 10 ³ Pa, and 200 The value of the loss tangent (tan δ) at ° C. was 1.2. The temperature at which the loss elastic modulus G ″ of the toner particles at a frequency of 1 Hz is 10 ³ Pa is 170 ° C., which is the same temperature as the melting point (Tm) of the polylactic acid resin A. Further, the volume of the toner obtained The average particle size was 6.7 μm, and the coefficient of variation (CV value) was 24%.

(Comparative Example 7)
In the pre-mixing step, as binder resin (100 parts by weight), instead of polyester resin A as a main component, styrene-acrylic resin D (glass transition temperature (Tg): 62 ° C., softening temperature (T _1/2 ): The toner of Comparative Example 7 (14.2 kg) was produced in the same manner as in Example 1 except that 127 ° C., peak top molecular weight 12000, acid value 10.2, THF insoluble content 7%) were used.

The obtained toner particles have a loss elastic modulus G ″ at 120 ° C. of 4.3 × 10 ⁴ Pa and a loss elastic modulus G ″ at 200 ° C. of 7.8 × 10 Pa. The value of loss tangent (tan δ) was 12. The temperature at which the loss elastic modulus G ″ of the toner particles at a frequency of 1 Hz becomes 10 ³ Pa is 126 ° C., and the melting point (Tm) of the polylactic acid resin A is 44 ° C. higher. The toner had a volume average particle diameter of 6.7 μm and a coefficient of variation (CV value) of 3.3%.

(Comparative Example 8)
In the pre-mixing step, 83.3% by weight (92.0 parts by weight) of polyester resin C is used as the binder resin (100 parts by weight) instead of polyester resin A as the main component, and 7.2% by weight of polylactic acid resin A is used. 13.2 kg of the toner of Comparative Example 8 was produced in the same manner as in Example 1 except that% (8.0 parts by weight) was used.

The obtained toner particles have a value of loss elastic modulus G ″ at 120 ° C. of 5.9 × 10 ⁵ Pa, a value of loss elastic modulus G ″ at 200 ° C. of 9.7 × 10 ⁴ Pa, 200 The loss tangent (tan δ) value at 3.1 ° C. was 3.1. The temperature at which the loss elastic modulus G ″ of the toner particles at a frequency of 1 Hz becomes 10 ³ Pa is 168 ° C., and the melting point (Tm) of the polylactic acid resin C is 2 ° C. Further, the toner obtained The volume average particle diameter was 6.8 μm, and the coefficient of variation (CV value) was 23%.

In the toners of Examples 1 to 4 and Comparative Examples 1 to 8, the type of resin as a main component (referred to as “main component resin” in Table 1), the type of polylactic acid resin as a crystalline resin, and the content thereof The difference between the melting point (Tm), the melting point (Tm) of the polylactic acid resin, and the temperature at which the loss elastic modulus G ″ of the toner particles at a frequency of 1 Hz becomes 10 ³ Pa (referred to as “temperature” in Table 1). Table 1 shows values of “Tm-temperature”), viscoelasticity of toner particles, and toner particle size distribution.

[Evaluation]
The toners of Examples 1 to 4 and Comparative Examples 1 to 8 were evaluated for storage stability, fixability, fixing strength, and light transmittance as follows.

[Storage stability]
Put 28g-30g of toner into three 50ml plastic bottles, put them in a constant temperature and humidity chamber set at 50 ° C and 10% RH with the lid of the plastic bottle closed, and take out one toner every 24 hours. The bulk density of the toner was measured according to JIS K-5101-12-1 using a bulk specific gravity measuring instrument (manufactured by Tsutsui Riken Kikai Co., Ltd.). Initially, the bulk density after 24 hours, 48 hours, and 72 hours was measured, and the variation rate was calculated based on the following formula (4). A toner having a smaller variation rate indicates better storage stability.
(Variation rate) = (bulk density after 72 hours) / (initial bulk density) × 100 (4)

The evaluation criteria for storage stability are shown below.
○: The fluctuation rate is 90% or more.
Δ: The fluctuation rate is 80% or more and less than 90%.
X: Fluctuation rate is less than 80%.

[Fixability]
Using a ferrite core carrier having a volume average particle size of 45 μm as a carrier, a V-type mixer / mixer (commodity) so that the coverage of the toners of Examples 1 to 4 and Comparative Examples 1 to 8 with respect to the carrier is 60%, respectively. Name: V-5, manufactured by Tokuju Kogyo Co., Ltd.) for 20 minutes to prepare a two-component developer.

Using the two-component developer obtained by modifying a color composite machine (trade name: MX-2700, manufactured by Sharp Corporation), a recording paper (trade name: PPC paper SF-4AM3, Sharp) that is a recording medium is used. Co., Ltd.), a sample image including a rectangular solid image portion having a length of 20 mm and a width of 50 mm has a toner adhesion amount of 0.5 mg / cm ² in a solid image portion in an unfixed state. Thus, an unfixed image was prepared. The non-offset area of the obtained unfixed image was evaluated using an external fixing device prepared using a fixing unit of a color multifunction peripheral. The fixing process speed was 124 mm / second, the temperature of the fixing roller was increased from 130 ° C. in increments of 10 ° C., and the temperature range in which neither low-temperature offset nor hot offset occurred was defined as a non-offset range, and used as an index of fixability.

The definition of the high temperature and low temperature offset is that the toner does not fix to the recording paper during fixing, but adheres to the recording paper after the roller makes a full turn while adhering to the fixing roller. The evaluation criteria for fixability are shown below.
○: The non-offset region is 50 ° C. or higher.
(Triangle | delta): A non-offset area | region is 30 degreeC or more and less than 50 degreeC.
X: The non-offset area is less than 30 ° C.

[Fixing strength]
A fixed image fixed at a temperature 30 ° C. lower than the temperature at which the loss elastic modulus G ″ of the toner at a frequency of 1 Hz is 10 ³ Pa was prepared in the same manner as the evaluation of the fixability. Gluing tape (Model No .: 810-3-12, manufactured by Sumitomo 3M) is lightly affixed, and the weight of 837g cylindrical type (outer diameter 75mm, height 50mm) is fixed by rotating 3 times on the mending tape. After rubbing on the image, the mending tape was peeled off.The optical density of the fixed image before and after the mending tape was peeled off was measured by spectrophotometric densitometer (trade name: X-rite 938, manufactured by X-rite). ) And the fixing strength was evaluated.

  The value represents the ratio between the optical density of the fixed image after peeling the mending tape and the optical density of the fixed image before sticking the mending tape, (optical density of the fixed image after peeling the tape / before tape sticking). The value of (fixed image optical density) × 100 was defined as the fixing strength ratio. The larger the value of the fixing strength rate, the better the fixing strength and the wider the temperature range that can be fixed.

Evaluation criteria for fixing strength are shown below.
○: The fixing strength rate is 80% or more.
X: The fixing strength rate is less than 80%.

〔Optical transparency〕
A two-component developer was prepared in the same manner as in the evaluation of fixability. Using a modified color MFP (trade name: MX-2700, manufactured by Sharp Corporation), adjusting the toner adhesion amount to 1.7 mg / cm ² on the OHP sheet, and fixing the sample image unfixed An image was prepared and a fixed image was prepared. The HAZE value of the obtained fixed image was measured using a HAZE meter model NDH2000 (trade name, manufactured by Nippon Denshoku Industries Co., Ltd.), and light transmittance was evaluated. The smaller the HAZE value, the better the light transmittance.

The evaluation criteria of light transmittance are shown below.
○: HAZE value is less than 20.
Δ: HAZE value is 20 or more and less than 25.
X: HAZE value is 25 or more.

〔Comprehensive evaluation〕
The evaluation criteria for comprehensive evaluation are as follows.
○: Good. All evaluation results do not have x and Δ.
Δ: No problem in actual use. All evaluation results have no x and Δ is 1 or more.
X: Defect. There is a cross in at least one of the evaluation results.

  Table 2 shows the evaluation results and overall evaluation of storage stability, fixability, fixing strength, and light transmittance evaluated as described above.

  From the results shown in Table 2, it is clear that the toners of Examples 1 to 4 in the present invention are superior to the toners of Comparative Examples 1 to 8 as follows.

The toners of Examples 1 to 4 are configured so that the binder resin includes the polyester resin A as a main component and the polylactic acid resins A to C as a crystalline resin. 1 to 50 parts by weight with respect to 100 parts by weight of the binder resin, and the melting point is 5 ° C. to 10 ° C. than the temperature at which the loss elastic modulus G ″ of the toner at a frequency of 1 Hz becomes 10 ³ Pa. Due to the high temperature, good results were obtained in storage stability, fixing property, fixing strength and light transmittance.

  On the other hand, in Comparative Example 1, since the polylactic acid resin A, which is a crystalline resin, was too much as 60 parts by weight with respect to 100 parts by weight of the binder resin, the binder resin became too hard and could be melt-kneaded. There wasn't. Therefore, evaluation was impossible.

Since the toners of Comparative Examples 2 to 4 were melt-kneaded using an extruder, polylactic acid was not sufficiently dispersed in the toner, and therefore the melting point (Tm) of the crystalline resin was a loss of toner at a frequency of 1 Hz. The elastic modulus G ″ exceeded a temperature 10 ° C. higher than the temperature at which 10 ³ Pa was reached. Therefore, good results were not obtained in storage stability, fixing property, fixing strength and light transmittance.

Since the toners of Comparative Examples 5 and 7 use polyester resins B and D as resins that are the main component of the binder resin, respectively, the loss elastic modulus G ″ of the toner when the melting point (Tm) of the crystalline resin is 1 Hz is used. The temperature was higher by 10 ° C. than the temperature at which 10 ³ Pa. Therefore, the loss tangent exceeded 10 and good results were not obtained in storage stability, fixability, fixing strength and light transmittance.

In the toners of Comparative Examples 6 and 8, since polyester resin C is used as the resin that is the main component of the binder resin, the melting point (Tm) of the crystalline resin is 10 ^{3 and} the loss elastic modulus G ″ of the toner at a frequency of 1 Hz is 10 ^3. The light transmittance deteriorated because the temperature was lower than the temperature higher by 5 ° C. than the temperature at which Pa was reached. The loss elastic modulus G ″ (120 ° C.) exceeded 10 ⁵ Pa, and the fixability and fixing strength deteriorated.

It is a flowchart which shows an example of the procedure in the manufacturing method of the toner of this invention. 1 is a cross-sectional view schematically showing a configuration of an image forming apparatus of the present invention. It is sectional drawing which shows typically an example of a structure of the developing device of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Toner image forming means 3 Transfer means 4 Fixing means 5 Recording medium supply means 6 Ejecting means 11 Photosensitive drum 12 Charging means 13 Exposure unit 14 Developing means 15 Cleaning unit 20 Developing tank 21 Toner hopper 25 Intermediate transfer belt 26 Drive Roller 27 Follower roller 28 Intermediate transfer roller 29 Transfer belt cleaning unit 30 Transfer roller 31 Fixing roller 32 Pressure roller 35 Automatic paper feed tray 36 Pickup roller 37 Transport roller 38 Registration roller 39 Manual paper feed tray 40 Discharge roller 41 Discharge tray

Claims (10)

A toner comprising at least a binder resin and a colorant,
The binder resin is configured to include a resin as a main component and a crystalline resin containing biomass,
The crystalline resin is contained in an amount of 1 to 50 parts by weight with respect to 100 parts by weight of the binder resin, and the melting point of the crystalline resin is such that the loss elastic modulus G ″ of the toner at a frequency of 1 Hz is 10 ³ Pa. A toner having a temperature 5 to 10 ° C. higher than The toner according to claim 1, wherein the crystalline resin includes a unit represented by the following formula (1).
_{- [O-CH (CH 3} ) -CO] n - ... (1)
(In the formula, n represents a positive integer.)   The toner according to claim 1, wherein the resin as a main component is a polyester resin. The loss elastic modulus G ″ at 120 ° C. of the toner is 10 ⁵ Pa or less, the loss elastic modulus G ″ at 200 ° C. is 10 ¹ Pa or more, and the loss elastic modulus G ″ at 200 ° C. is divided by the storage elastic modulus G ′. The toner according to claim 1, wherein the loss tangent as a value is 10 or less. A method for producing the toner according to any one of claims 1 to 4, comprising:
A pre-mixing step of preparing a mixture by mixing at least a resin as a main component and a binder resin comprising a crystalline resin containing biomass and a colorant;
A melt-kneading step of melt-kneading a mixture containing a crystalline resin in an amount of 1 part by weight or more and 50 parts by weight or less with respect to 100 parts by weight of a binder resin;
A pulverization step of pulverizing the melt-kneaded product to produce a pulverized product;
And a classification step of removing excessively pulverized material and coarse powder from the pulverized material.   6. The method for producing a toner according to claim 5, wherein in the melt-kneading step, the mixture is melt-kneaded using a two-roll type continuous kneader.   A two-component developer comprising the toner according to any one of claims 1 to 4 and a carrier.   A developing device that performs development using the toner according to claim 1 or the two-component developer according to claim 7.   An image forming apparatus comprising the developing device according to claim 8.   The image forming apparatus according to claim 9, further comprising a fixing unit configured to thermally melt and fix the toner image formed on the recording medium.

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